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Chemistry

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Overview

Chemistry is one of Jeopardy!'s most substantial science topics, with 1,185 clues and 15 Final Jeopardy appearances across the show's history. It is also one of the most lopsided in difficulty distribution: 70.5% of Chemistry clues appear in the Double Jeopardy round versus only 28.2% in the Jeopardy round, signaling that the writers consider this harder-than-average material. Daily Double accuracy sits at just 65%, well below the show's overall DD average, confirming that Chemistry punishes guessing.

The raw categories tell an interesting story about how the show packages this topic. "CHEMISTRY" itself accounts for 325 clues, but the real workhorse is "THE ELEMENTS" at 194 clues, followed by "METALS" at 147. Smaller specialty categories add flavor: "ELEMENTARY" (20), plus creative one-offs like "ELEMENTAL LATIN," "ELEMENTAL ETYMOLOGY," "OLD NAMES FOR CHEMICAL ELEMENTS," and the delightful "REJECTED ELEMENT NAMES." The heavy emphasis on elements over chemical processes means that studying the periodic table pays outsized dividends.

The gimmes: Carbon (23 clues, 95.2%), Hydrogen (14, 100%), Iron (16, 100%), Helium (16, 93.8%), Aluminum (16, 93.8%), Copper (15, 93.3%), Gold (19, 90.5%), Mercury (27, 88.9%), Platinum (9, 100%), Sodium (11, 100%), Uranium (8, 100%), Titanium (8, 100%), Nickel (8, 100%), Sulfur (7, 100%), Silicon (7, 100%), Chlorine (7, 100%), Potassium (5, 100%), Tungsten (6, 100%), Cobalt (6, 100%), Magnesium (5, 100%), Argon (5, 100%), Radon (5, 100%), Thorium (5, 100%), Curium (5, 100%), water (6, 100%), rust (5, 100%), distillation (5, 100%).

The stumper zone: Fluorine (5 clues, 66.7% wrong), Phosphorus (5, 50% wrong), Radium (6, 44.4% wrong), Zinc (7, 42.9% wrong), Silver (20, 41.7% wrong), Nitrogen (7, 41.7% wrong), Zirconium (5, 41.7% wrong), Xenon (5, 40% wrong), Tin (10, 40% wrong), Polonium (5, 40% wrong).

Study strategy: The single most important thing you can do for Chemistry is learn the Latin element names and their modern equivalents. When clues reference "argentum," "stannum," "natrium," or "hydrargyrum," wrong rates spike dramatically; this is the #1 stumper mechanism in the entire topic. After that, learn the periodic table groups (noble gases, halogens, alkali metals) and the discovery stories behind frequently tested elements. Finally, study the 15 Final Jeopardy appearances, which lean heavily on etymology, naming origins, and discovery history.


The Heavy Hitters: Most-Tested Elements

Eleven elements account for a disproportionate share of Chemistry clues. These are the answers that appear again and again across regular play, Daily Doubles, and Final Jeopardy. Learning every angle the show uses for each one is the foundation of Chemistry preparation.

Mercury ~27 clues · 88.9% correct

Mercury is the single most-tested element in all of Jeopardy's Chemistry categories, and the clue angles are diverse. The most common approach is its physical properties: mercury is the only metal that is liquid at room temperature, a fact that appears in dozens of clues across difficulty levels. Its chemical symbol Hg comes from "hydrargyrum," the Latinized form of the Greek "hydrargyros" meaning "water silver" or "liquid silver" and this etymology is a regular mid-to-high-value clue.

The show also tests mercury through its ores and pigments. Cinnabar (mercuric sulfide, HgS) is the principal ore of mercury and was ground to produce vermilion, the brilliant red pigment used by Renaissance painters. Clues connecting cinnabar to mercury or vermilion to cinnabar are standard $800–$1,200 fare. Mercury's use in thermometers, its toxicity (as methylmercury in fish), and its role in hat-making ("mad as a hatter") also appear. The planet Mercury shares its name because the element, like the Roman messenger god, is quick and elusive.

Despite its high frequency, mercury maintains a strong 88.9% accuracy rate, likely because the "liquid metal" angle is so distinctive that contestants rarely confuse it with anything else.

Lead ~26 clues · 76.7% correct

Lead appears almost as often as mercury but with notably lower accuracy. The primary stumper mechanism is its Latin name, "plumbum," from which we get the chemical symbol Pb and the English word "plumber" (Roman plumbers worked with lead pipes). When clues use the Pb symbol or reference plumbum, wrong rates climb.

Other common clue angles include lead's density and its use as radiation shielding, lead aprons in dental X-rays, lead-lined walls in nuclear facilities. The environmental angle also appears: tetraethyl lead was added to gasoline beginning in the 1920s and phased out decades later. Lead's role in ancient Rome is another favorite; Romans used lead in pipes, cookware, and even as a wine sweetener (lead acetate, called "sugar of lead"), contributing to theories about lead poisoning's role in Rome's decline.

Lead pencils are a classic trick clue: pencil "lead" is actually graphite (a form of carbon), not lead at all. The show tests this at least once every few seasons.

Watch out: Lead drops to the mid-70s in accuracy primarily because of the plumbum/Pb angle. If a clue asks for the element whose symbol is Pb, or whose Latin name gives us a word for a pipe worker, many contestants freeze.

Carbon ~23 clues · 95.2% correct

Carbon is one of the highest-accuracy elements in the topic, and for good reason: its clue angles are well-known and distinctive. Carbon is the basis of all organic chemistry, the "building block of life." Its allotropes provide multiple answer paths: diamond (the hardest natural substance), graphite (pencil "lead" and lubricant), buckminsterfullerene (the "buckyball," a 60-carbon sphere named after architect Buckminster Fuller), and soot/charcoal.

The Latin word "carbo" means "coal" or "charcoal," giving rise to the element name. Carbon-14 dating is a regular mid-value clue. Carbon dioxide (CO2) and carbon monoxide (CO) provide additional angles. The show also likes the fact that carbon has atomic number 6 and that it can form more compounds than any other element except hydrogen.

Silver ~20 clues · 58.3% correct

Silver's 58.3% accuracy makes it one of the trickiest "common" elements, and the reason is almost entirely its Latin name. "Argentum" gives silver the symbol Ag; and when clues approach from the Latin angle, contestants frequently miss. Argentina was named for the silver its Spanish explorers hoped to find there. The mineral argentite (silver sulfide, Ag2S) is its principal ore. The Comstock Lode in Nevada was one of the richest silver strikes in American history.

Silver's physical properties also appear: it has the highest electrical conductivity and highest thermal conductivity of any element. Sterling silver is 92.5% silver alloyed with copper. Silver nitrate was used in early photography, and colloidal silver has been marketed (dubiously) as a health supplement.

Watch out: Silver is a top-five stumper among common elements. The argentum/Ag connection is the primary failure point. If you hear "argentum," "Ag," "Argentina," or "argentite" in a Chemistry clue, the answer is almost certainly silver.

Gold ~19 clues · 90.5% correct

Gold's Latin name "aurum" gives it the symbol Au, and unlike silver's argentum, contestants handle this one well. The etymology appears regularly: "aurora" (dawn) shares the same root, as gold was associated with the color of sunrise. South Africa has historically been the world's leading gold producer, and the California Gold Rush of 1849 is a crossover with American History.

Gold is tested for its physical properties: it is the most malleable and ductile metal, meaning it can be hammered into extremely thin sheets (gold leaf) or drawn into fine wire. A single ounce can be beaten into a sheet covering 100 square feet. Gold's atomic number is 79 and its density makes it useful as a standard for purity, measured in karats, with 24-karat being pure gold.

Iron ~16 clues · 100% correct

Iron is a perfect gimme with 100% accuracy across all 16 appearances. Its Latin name "ferrum" gives it the symbol Fe, and the prefix "ferro-" appears in words like ferrous, ferric, and ferromagnetic. The human body contains about 4 grams of iron, mostly in hemoglobin. The Iron Age followed the Bronze Age. Wrought iron, cast iron, and pig iron are all tested. Rust is iron oxide (Fe2O3), and "rust" itself appears as a separate answer with 100% accuracy.

Helium ~16 clues · 93.8% correct

Helium was discovered in 1868 not on Earth but in the Sun's chromosphere during a solar eclipse; the French astronomer Pierre Janssen and English astronomer Joseph Norman Lockyer independently observed a bright yellow spectral line that didn't match any known element. The name comes from "helios," the Greek word for sun. This discovery story is a Final Jeopardy favorite.

Helium is the second-lightest element (after hydrogen) and the second most abundant in the universe. Its most familiar use is in party balloons and Macy's Thanksgiving Day Parade balloons. Inhaling helium temporarily raises the pitch of your voice because sound travels faster through helium than through air. Helium is a noble gas, colorless, odorless, and almost entirely nonreactive. Liquid helium is used as a coolant for superconducting magnets in MRI machines.

Aluminum ~16 clues · 93.8% correct

Aluminum (or aluminium, depending on which side of the Atlantic you're on) is another near-perfect gimme. It is the most abundant metal in Earth's crust. The Washington Monument is capped with a small pyramid of aluminum, when it was completed in 1884, aluminum was more precious than gold. The Hall-Heroult process, developed in 1886, made aluminum cheap to produce. Bauxite is its principal ore. Aluminum foil, aluminum cans, and the metal's light weight are all standard low-value clue angles.

Oxygen ~15 clues · 70% correct

Oxygen's 70% accuracy is surprisingly low for such a familiar element. The stumper angles involve its chemistry rather than its identity: ozone (O3) is an allotrope of oxygen, and clues that approach oxygen through ozone or through its role in combustion (oxidation) can trip contestants up. Oxygen makes up about 21% of Earth's atmosphere (nitrogen is 78%). Antoine Lavoisier named it from Greek roots meaning "acid-former" because he incorrectly believed all acids contained oxygen. Joseph Priestley is generally credited with its discovery in 1774.

Copper ~15 clues · 93.3% correct

Copper's Latin name "cuprum" gives it the symbol Cu, derived from "Cyprium aes" (metal of Cyprus), because the ancient Romans mined it extensively on that island. Copper is the traditional gift for a 7th wedding anniversary. The Statue of Liberty is clad in copper, which has oxidized to its distinctive green patina (verdigris). Copper is an excellent conductor of electricity, second only to silver. Bronze is an alloy of copper and tin; brass is copper and zinc.

Hydrogen ~14 clues · 100% correct

Another perfect gimme. Hydrogen is element number 1 on the periodic table; the lightest and most abundant element in the universe. Its name means "water-former" (Greek "hydro" + "genes"). Hydrogen peroxide (H2O2) is a common antiseptic. The Haber-Bosch process combines hydrogen and nitrogen to manufacture ammonia, one of the most important industrial chemical processes ever developed. The Hindenburg disaster involved hydrogen gas. Heavy hydrogen (deuterium) has one neutron in addition to the single proton found in ordinary hydrogen.


The Periodic Table Mid-Tier

Below the eleven most-tested elements sits a rich middle tier of 17 elements that appear between 6 and 11 times each. These are still frequent enough to be worth dedicated study, and several harbor serious stumper potential.

Sodium ~11 clues · 100% correct

A perfect gimme despite having the unfamiliar Latin name "natrium" (symbol Na). Sodium appears in table salt (sodium chloride, NaCl), baking soda (sodium bicarbonate, NaHCO3), and lye (sodium hydroxide, NaOH). The medical condition hyponatremia (dangerously low sodium levels) occasionally surfaces in high-value clues. Sodium is an alkali metal that reacts violently with water, producing hydrogen gas and enough heat to ignite it. The brilliant yellow-orange flame of sodium is responsible for the color of many streetlights.

Plutonium ~10 clues · 80% correct

Plutonium has atomic number 94 and was named for Pluto, then considered the ninth planet, following the naming convention of uranium (Uranus) and neptunium (Neptune). It was first synthesized in 1940 at the University of California, Berkeley by Glenn Seaborg's team. Plutonium-239 is the fissile isotope used in nuclear weapons; the "Fat Man" bomb dropped on Nagasaki used a plutonium core. Its symbol is Pu, which Seaborg reportedly chose with a wink at the exclamation "P.U.!"

Tin ~10 clues · 60% correct

Tin is a significant stumper, and the mechanism is entirely its Latin name. "Stannum" gives tin the symbol Sn, and derivatives like "stannous" appear in chemistry: stannous fluoride is the active ingredient in some toothpastes. Tin is the major component of pewter (typically 85–99% tin). The "Tin Pan Alley" of American music publishing has nothing to do with the element, but the show occasionally makes the connection. Bronze is an alloy of copper and tin, one of humanity's first engineered metals.

Watch out: Tin's 40% wrong rate is driven almost entirely by "stannum" and "Sn" clues. When the show asks which element has the symbol Sn, contestants who haven't specifically studied Latin element names are lost.

Platinum ~9 clues · 100% correct

A perfect gimme. Platinum's name comes from the Spanish "platina," meaning "little silver." It is denser than gold, extremely resistant to corrosion, and used in catalytic converters, jewelry, and laboratory equipment. Platinum records in the music industry require one million copies sold. South Africa is the world's leading producer.

Neon ~9 clues · 77.8% correct

Neon's name comes from the Greek "neos" meaning "new." It is a noble gas discovered by William Ramsay and Morris Travers in 1898. Neon signs produce their characteristic reddish-orange glow when electricity passes through neon gas in a tube. Despite common usage, most "neon signs" of other colors actually use different gases (argon for blue, mercury vapor for other colors). True neon produces only red-orange light.

Uranium ~8 clues · 100% correct

Another perfect gimme. Uranium was named for the planet Uranus, which had been discovered just eight years before Martin Klaproth identified the element in 1789. Uranium-235 is the fissile isotope used in nuclear reactors and the "Little Boy" atomic bomb dropped on Hiroshima. Yellowcake is a concentrated uranium powder. Pitchblende (uraninite) is the primary ore, famously studied by Marie and Pierre Curie.

Titanium ~8 clues · 100% correct

Named for the Titans of Greek mythology, titanium is as strong as steel but nearly half as heavy; this strength-to-weight ratio makes it essential in aerospace engineering. It is also biocompatible, meaning the human body does not reject it, so it is widely used in joint replacements and dental implants. Titanium dioxide (TiO2) is the white pigment in most white paints and sunscreens.

Nickel ~8 clues · 100% correct

The element nickel was named from the German "Kupfernickel" ("Old Nick's copper" or "devil's copper"), because medieval German miners cursed the reddish-brown ore that looked like copper but yielded no copper when smelted. The U.S. five-cent coin is actually 75% copper and only 25% nickel. Nickel is used in stainless steel alloys and nickel-cadmium batteries.

Nitrogen ~7 clues · 58.3% correct

Nitrogen is the most abundant gas in Earth's atmosphere at approximately 78%, yet its 58.3% accuracy suggests contestants often confuse it with oxygen. The name comes from the Greek "nitron genes" meaning "niter-forming" (niter being potassium nitrate, or saltpeter). Liquid nitrogen, at -196°C (-321°F), is used in cryogenics. The Haber-Bosch process combines nitrogen and hydrogen to produce ammonia. Nitrogen narcosis ("rapture of the deep") affects scuba divers at great depths.

Watch out: When a clue says "the most plentiful gas in the air" or "making up 78% of the atmosphere," many contestants reflexively answer oxygen. The answer is nitrogen.

Zinc ~7 clues · 57.1% correct

Zinc is a surprisingly effective stumper. Its name may derive from the German "Zinke" meaning "prong" or "tooth," referring to the pointed shape of zinc crystals. Galvanizing (coating iron or steel with zinc to prevent rust) is the most common clue angle. Brass is an alloy of copper and zinc. Zinc oxide is used in sunscreen and calamine lotion. Despite being a familiar household name, contestants miss zinc 42.9% of the time, often when the clue approaches from the galvanizing or brass angle.

Watch out: Zinc's German etymology ("prong") and its role in galvanizing are the two angles that trip contestants most often.

Sulfur ~7 clues · 100% correct

A perfect gimme. Sulfur (or sulphur) was historically known as "brimstone" "fire and brimstone" in the Bible refers to sulfur's tendency to burn with a choking, acrid smell. Sulfur dioxide (SO2) is a major air pollutant. Sulfuric acid (H2SO4) is the most widely produced industrial chemical in the world. Sulfur's atomic number is 16, and it is a bright yellow solid at room temperature.

Silicon ~7 clues · 100% correct

Another perfect gimme. Silicon (not silicone, the synthetic polymer) is the second most abundant element in Earth's crust after oxygen. Silicon Valley takes its name from the silicon used in semiconductor chips. Silicon dioxide (SiO2) is quartz, the main component of sand and glass. Silicon's atomic number is 14.

Chlorine ~7 clues · 100% correct

Chlorine's name comes from the Greek "chloros" meaning "pale green," describing the color of chlorine gas. It is a halogen, used to disinfect drinking water and swimming pools. Sodium chloride is table salt. Chlorine gas was used as a chemical weapon in World War I. Hydrochloric acid (HCl) is produced naturally in the human stomach.

Tungsten ~6 clues · 100% correct

Tungsten has the highest melting point of any element (3,422°C / 6,192°F), which is why it is used in incandescent light bulb filaments. Its chemical symbol W comes from "wolfram," the German name for the element (from "wolframite," its ore). The name "tungsten" is Swedish for "heavy stone." This dual-naming situation (tungsten in English, wolfram on the periodic table) is a natural clue angle, though contestants handle it well.

Arsenic ~6 clues · 83.3% correct

Arsenic has been called "the king of poisons and the poison of kings" because of its long history as a murder weapon; it is odorless and tasteless when dissolved. The play and film Arsenic and Old Lace features elderly women who poison lonely old men with elderberry wine laced with arsenic. Napoleon may have been slowly poisoned by arsenic in the green wallpaper of his room on St. Helena (the pigment Scheele's Green contained copper arsenate). Arsenic appears in Final Jeopardy paired with zinc.

Radium ~6 clues · 55.6% correct

Radium is a significant stumper at 44.4% wrong. Marie Curie discovered radium (along with polonium) by painstakingly processing tons of pitchblende ore. Its name comes from the Latin "radius" meaning "ray," reflecting its intense radioactivity. Radium's symbol is Ra. Radium was once used in luminous watch dials, leading to the tragic story of the "Radium Girls" factory workers who developed radiation sickness from licking their paintbrushes to sharpen the tips. Radon, the radioactive noble gas, is a decay product of radium.

Watch out: Radium's 44.4% wrong rate makes it one of the topic's biggest stumpers. Contestants often confuse it with radon, uranium, or plutonium. The Marie Curie / pitchblende connection is the key to nailing it.

Cobalt ~6 clues · 100% correct

Cobalt's name comes from the German "Kobold" meaning "goblin" or "evil spirit" medieval miners blamed cobalt ores for the poisonous fumes they emitted when smelted (actually arsenic impurities). Cobalt blue is one of the most distinctive pigments in art. Cobalt-60 is a radioactive isotope used in radiation therapy. The element's atomic number is 27.


Noble Gases, Halogens & Element Groups

Jeopardy loves testing elements by their periodic table groups. Knowing which elements belong to which family (and the group's defining characteristics) turns many $1,200–$2,000 clues into confident responses.

Noble Gases ~5 clues for "noble gases" · 80% correct

The noble gases occupy Group 18 (the rightmost column) of the periodic table: helium, neon, argon, krypton, xenon, and radon. They were originally called "inert gases" because they were thought to be completely nonreactive, but xenon compounds were synthesized in the 1960s, so the name was changed to "noble" (as in "too noble to react with common elements"). All are colorless, odorless, and monatomic.

Helium (16 clues, 93.8%), The lightest noble gas. Discussed in detail in the Heavy Hitters section. Key FJ angle: discovered in the Sun before it was found on Earth.

Neon (9, 77.8%), Produces a characteristic red-orange glow in discharge tubes. From Greek "neos" meaning "new."

Argon (5, 100%), The most abundant noble gas in Earth's atmosphere (about 0.93%). Its name comes from the Greek "argon" meaning "idle" or "lazy," reflecting its lack of reactivity. Used in welding and in incandescent light bulbs to prevent the filament from oxidizing.

Krypton (5, 60%), From the Greek "kryptos" meaning "hidden." Superman's home planet Krypton shares the name but is fictional. Krypton is used in certain fluorescent lights and photographic flash equipment. Its 60% accuracy suggests the Superman connection creates confusion rather than helping.

Xenon (5, 60%), From the Greek "xenos" meaning "strange" or "foreign." Used in high-intensity arc lamps, including those in IMAX projectors. Xenon was the first noble gas shown to form compounds, when Neil Bartlett synthesized xenon hexafluoroplatinate in 1962.

Watch out: Xenon (40% wrong) and krypton (40% wrong) are the noble gas stumpers. The Greek etymology clues ("strange/foreign" for xenon, "hidden" for krypton) are the angles that trip people up most. Contestants who know the Superman connection sometimes guess krypton incorrectly for other noble gas clues.

Radon (5, 100%), A radioactive noble gas and a decay product of radium. Radon testing in homes is common because the gas can seep through foundations and accumulate to dangerous levels. It is the heaviest noble gas. Appeared in Final Jeopardy with 3/3 correct; one of the easier FJ chemistry clues.

Halogens

The halogens occupy Group 17: fluorine, chlorine, bromine, iodine, and astatine. The name comes from Greek roots meaning "salt-forming," because halogens react with metals to form salts (sodium chloride, potassium iodide, etc.). They are among the most reactive nonmetals.

Fluorine (5, 33.3%), The most reactive element in the entire periodic table and the #1 stumper in all of Chemistry by wrong percentage. Its name comes from the Latin "fluere" meaning "to flow," because the mineral fluorite (calcium fluoride) was used as a flux in smelting to make slag flow more easily. Fluoride in toothpaste and drinking water comes from fluorine compounds. Despite fluoride being a household word, contestants cannot connect it back to the element fluorine when the clue uses the Latin etymology.

Watch out: Fluorine has a staggering 66.7% wrong rate, two out of three contestants miss it. The "Latin for to flow" clue is the killer. If you hear "flow" or "flux" in a Chemistry clue, think fluorine.

Chlorine (7, 100%), Discussed in the Mid-Tier section. A gimme.

Bromine, Along with mercury, one of only two elements that are liquid at room temperature. Its name comes from the Greek "bromos" meaning "stench."

Iodine, Its name comes from the Greek "ioeides" meaning "violet-colored," describing the color of iodine vapor. Iodine deficiency causes goiter (swelling of the thyroid gland), which is why table salt is iodized.

Alkali Metals

Group 1 of the periodic table: lithium, sodium, potassium, rubidium, cesium, and francium. All are soft, silvery metals that react vigorously (sometimes explosively) with water. Sodium and potassium are the most-tested members.

Sodium (11, 100%), Discussed in the Mid-Tier section. A gimme despite its unfamiliar symbol Na (from "natrium").

Potassium (5, 100%), Its symbol K comes from "kalium," the Latinized form of the Arabic "qali" meaning "alkali." Bananas are famously rich in potassium. Potassium is essential for nerve and muscle function; potassium chloride is used in lethal injection protocols.

The "Element Groups" Clue Pattern

The show frequently tests group membership: "Name a noble gas," "This group of elements in Group 17 are known as salt-formers," or "Lithium, sodium, and potassium are all in this group." The key groups to know:

  • Noble gases (Group 18): He, Ne, Ar, Kr, Xe, Rn, nonreactive, rightmost column
  • Halogens (Group 17): F, Cl, Br, I, At, salt-formers, very reactive nonmetals
  • Alkali metals (Group 1): Li, Na, K, Rb, Cs, Fr, soft metals, explosive in water
  • Alkaline earth metals (Group 2): Be, Mg, Ca, Sr, Ba, Ra, less reactive than alkali metals
  • Transition metals: the large central block, includes iron, copper, gold, silver, platinum
  • Lanthanides/rare earths: the top row pulled out below the table, includes europium, curium
  • Actinides: the bottom row pulled out below, includes uranium, plutonium, thorium

The term "noble gases" itself appears as an answer roughly 5 times (80% correct), and "halogens" appears about 4 times. Knowing these group names and their defining properties is essential for the $1,000+ clue values.


Chemistry Concepts & Scientists

Beyond the elements themselves, Jeopardy tests fundamental chemistry concepts, laboratory processes, and the scientists who shaped the field. These answers appear less frequently than individual elements but are reliable mid-to-high-value clue fodder.

Key Concepts & Substances

Water (6 clues, 100%), H2O is a perfect gimme. Clues typically involve its chemical formula, its role as the "universal solvent," or its unusual property of being less dense as a solid (ice floats). Water appeared in Final Jeopardy with a perfect 3/3 correct rate, when the FJ category is Chemistry, H2O is always a safe instinct.

Rust (5, 100%), Iron oxide, specifically Fe2O3. The chemical process of rusting is oxidation, iron reacting with oxygen and water. "What is rust?" is a gimme at any value level.

Electrons (5, 80%), Clues test electron configuration, valence electrons, and the electron's negative charge. J.J. Thomson discovered the electron in 1897 using cathode ray experiments.

Distillation (5, 100%), The process of separating mixtures by differences in boiling points. Fractional distillation is used to refine crude oil into gasoline, kerosene, and other products. Distilling spirits (whiskey, vodka) uses the same principle. A perfect gimme.

Noble gases (5, 80%), Discussed in the Element Groups section. The answer "noble gases" itself is tested when clues describe the group's properties.

Salt (~4 clues), Sodium chloride (NaCl). The word "salary" derives from "salarium," the Roman soldiers' allowance for purchasing salt. Salt appears in Chemistry clues about ionic bonding (Na+ and Cl- ions) and in crossover clues with History and Food/Drink.

Isotopes (~4 clues), Atoms of the same element with different numbers of neutrons. Carbon-12 and carbon-14 are the most commonly referenced isotopes. Deuterium is an isotope of hydrogen with one neutron.

Ammonia (~4 clues), NH3. Produced industrially by the Haber-Bosch process (combining nitrogen and hydrogen under high pressure and temperature). Used in fertilizers, cleaning products, and as a refrigerant. Its pungent smell is distinctive.

Acids (~4 clues), The pH scale measures acidity (below 7) and alkalinity (above 7). Sulfuric acid (H2SO4) is the most-produced industrial chemical. Hydrochloric acid (HCl) is in your stomach. Nitric acid (HNO3) and phosphoric acid (H3PO4, found in cola) also appear.

Absolute zero (~4 clues), The lowest possible temperature: 0 Kelvin, -273.15°C, or -459.67°F. At absolute zero, molecular motion theoretically ceases. Lord Kelvin (William Thomson) proposed the absolute temperature scale.

Teflon (~4 clues), Polytetrafluoroethylene (PTFE), discovered accidentally by Roy Plunkett in 1938 while working for DuPont. Known for its nonstick properties in cookware. "Teflon" as a metaphor for politicians to whom scandals don't stick is a crossover clue angle.

The Scientists

Antoine Lavoisier (~4 clues), Considered the "father of modern chemistry." Lavoisier disproved the phlogiston theory of combustion, identified oxygen and hydrogen as elements, and established the law of conservation of mass. He named oxygen (incorrectly believing all acids contained it, "oxy" + "genes" = "acid-former"). He was executed by guillotine during the French Revolution in 1794; the mathematician Lagrange reportedly said, "It took them only an instant to cut off his head, but France may not produce another such head in a century."

Marie Curie, Discovered polonium (named for her native Poland) and radium. She won two Nobel Prizes, in Physics (1903, shared with Pierre Curie and Henri Becquerel) and in Chemistry (1911, solo). She coined the term "radioactivity." Her notebooks are still so contaminated with radium that they must be kept in lead-lined boxes. Marie Curie is the most frequently referenced scientist in Chemistry FJ clues.

Dmitri Mendeleev, Created the first widely recognized periodic table in 1869, arranging elements by atomic weight and predicting the existence of then-undiscovered elements (which he named eka-boron, eka-aluminum, and eka-silicon, later identified as scandium, gallium, and germanium). The element mendelevium (Md, atomic number 101) was named in his honor.

Hennig Brand, A German alchemist who in 1669 became the first person to discover a new element: phosphorus. He isolated it by boiling and distilling large quantities of urine, producing a waxy white substance that glowed in the dark. This bizarre discovery story is a Final Jeopardy favorite.

Glenn Seaborg, Led the team at UC Berkeley that synthesized plutonium and several other transuranium elements. Seaborgium (Sg, element 106) was named after him while he was still alive; the only person so honored at the time.

Chemical Processes

Beyond distillation, the show tests several chemical processes:

  • Oxidation: Loss of electrons; rusting is the most common example. The opposite is reduction. Together they form "redox" reactions.
  • The Haber-Bosch process: Industrial synthesis of ammonia from nitrogen and hydrogen. Won Fritz Haber the Nobel Prize in Chemistry (1918) but he is also reviled as the "father of chemical warfare" for his work on poison gas in World War I.
  • Electrolysis: Using electricity to drive a non-spontaneous chemical reaction, such as splitting water into hydrogen and oxygen or extracting aluminum from bauxite (the Hall-Heroult process).
  • Catalysis: A catalyst speeds up a reaction without being consumed. Platinum and palladium in catalytic converters are the most common clue angle.
  • Sublimation: A solid turning directly into a gas without passing through the liquid phase. Dry ice (solid CO2) is the textbook example.

The Latin Name Challenge

If there is one single pattern that separates Chemistry experts from everyone else on Jeopardy, it is mastery of the Latin element names. This is not a minor footnote; it is THE dominant stumper mechanism across the entire topic. When clues use the Latin name, ask for the origin of a chemical symbol, or test the etymology of element-derived English words, wrong rates spike by 20–40 percentage points compared to the same element asked about through its physical properties.

The Complete Latin-to-Modern Map

Every contestant preparing for Jeopardy should have this table memorized cold:

Hydrargyrum → Mercury (Hg), From the Latinized Greek "hydrargyros" meaning "water silver" or "liquid silver." This is the most exotic-sounding Latin name, but mercury's 88.9% accuracy suggests the "liquid metal" angle is so strong that even etymology clues don't trip people up much.

Plumbum → Lead (Pb), Gives us "plumber" (Roman plumbers worked with lead pipes), "plumb line," "plumb bob," and "plumbing." When the clue asks what element's Latin name gives us a word for a pipe fitter, the answer is lead. This is a regular $800–$1,200 clue.

Argentum → Silver (Ag), Argentina was named for it. The mineral argentite is silver sulfide. The country, the mineral, and the symbol Ag are all regular clue angles, and silver's 41.7% wrong rate proves that contestants struggle with this one. If you hear "argentum," "Ag," or "Argentina" in a Chemistry context, the answer is silver.

Aurum → Gold (Au), Shares a root with "aurora" (dawn). Contestants handle this better than argentum, likely because the Au symbol and gold's cultural prominence make the connection more intuitive. The element's 90.5% accuracy confirms this.

Ferrum → Iron (Fe), Gives us "ferrous" (containing iron), "ferric," "ferromagnetic," and "ferret" (the animal, from Latin "furrittus" meaning "little thief" actually unrelated, but the show has made the false connection). Iron's 100% accuracy means even the Latin angle doesn't trip people up.

Stannum → Tin (Sn), This is where the stumper mechanics really bite. "Stannum" gives us "stannous" (as in stannous fluoride in toothpaste) and the symbol Sn. Tin's 40% wrong rate is almost entirely driven by Sn/stannum clues. If a clue mentions stannous fluoride, Sn, or stannum, the answer is tin.

Natrium → Sodium (Na), Despite having an unfamiliar Latin name, sodium maintains 100% accuracy, possibly because Na is well-known from chemistry class and the connection to sodium is frequently taught. "Hyponatremia" (low sodium) is a medical term derived from natrium.

Kalium → Potassium (K), From the Latinized Arabic "qali" meaning "alkali." The symbol K sometimes surprises contestants who expect Po or Pt (those belong to polonium and platinum, respectively). Potassium's 100% accuracy suggests the K symbol is well-known.

Stibium → Antimony (Sb), One of the more obscure Latin names. Antimony is a metalloid used in flame retardants and lead-acid batteries. The Sb symbol from stibium is a classic high-value clue.

Cuprum → Copper (Cu), From "Cyprium aes" (metal of Cyprus). Copper's 93.3% accuracy means this etymology doesn't cause much trouble, possibly because the Cu-copper connection is relatively intuitive.

Wolfram → Tungsten (W), Technically, "wolfram" is the German name, not Latin, but the principle is the same: the element we call tungsten in English has the symbol W from wolfram. Tungsten's 100% accuracy suggests this quirk is well-known among Jeopardy contestants, perhaps because the W symbol for tungsten is a common trivia question.

Why This Matters: The Accuracy Gap

Consider the contrast. When Mercury is clued as "the only metal that's liquid at room temperature," accuracy is near-perfect. When Silver is clued through its physical properties (highest conductivity, sterling silver), accuracy is solid. But when the same elements are clued through their Latin names ("From the Latin 'argentum,' this element has the symbol Ag") accuracy craters.

The elements with the biggest Latin-name-driven accuracy drops: 1. Silver (argentum/Ag): overall 58.3%, Latin clues are the primary drag 2. Tin (stannum/Sn): overall 60%, stannum clues are nearly always missed 3. Lead (plumbum/Pb): overall 76.7%, better than silver/tin but still well below the gimme tier

The elements where the Latin name does NOT cause problems: 1. Iron (ferrum/Fe): 100%, "ferrous" is common enough in everyday English 2. Gold (aurum/Au): 90.5%, Au is culturally prominent 3. Sodium (natrium/Na): 100%, Na is well-taught in school 4. Copper (cuprum/Cu): 93.3%, Cu is intuitive

Etymology as a Clue Angle

Beyond Latin names, the show tests element etymologies broadly:

  • Greek origins: Phosphorus ("light-bearing"), chlorine ("pale green"), bromine ("stench"), argon ("lazy/idle"), krypton ("hidden"), xenon ("strange/foreign"), helium ("sun")
  • Geographic origins: Copper (Cyprus), francium (France), germanium (Germany), polonium (Poland), americium (Americas), californium (California), berkelium (Berkeley), europium (Europe), scandium (Scandinavia), yttrium/erbium/terbium/ytterbium (all from Ytterby, Sweden)
  • Mythological origins: Titanium (Titans), thorium (Thor), vanadium (Vanadis/Freya), promethium (Prometheus), mercury (Mercury), plutonium (Pluto), neptunium (Neptune), uranium (Uranus), cerium (Ceres), palladium (Pallas Athena)

The geographic-origins angle is a particular FJ favorite. Europium (named for Europe) appeared in Final Jeopardy with only 1/3 contestants correct. Knowing which elements are named for countries, cities, or continents is high-value FJ preparation.


Final Jeopardy & Study Patterns

All 15 Final Jeopardy Appearances

Chemistry's 15 Final Jeopardy appearances cluster around three themes: element etymology and naming, discovery history, and unique physical properties. Here is the complete record:

The FJ Killer: Phosphorus (2 appearances, 0/6 total)

Phosphorus is the single deadliest Chemistry answer in Final Jeopardy. It has appeared twice (in 1991 and 2002) and all three contestants were wrong both times, for a combined 0/6 record. The clue angles involve its Greek name meaning "light-bearing" (phosphorus glows in the dark) and its discovery by Hennig Brand in 1669, who isolated it from concentrated urine. The word "phosphorescent" comes from phosphorus. If a Final Jeopardy clue in Chemistry mentions glowing, light-bearing, Hennig Brand, or 1669, the answer is phosphorus.

Watch out: Phosphorus is the most dangerous FJ answer in all of Chemistry. Its 0% success rate across two appearances makes it the ultimate stumper. Commit the Brand-1669-urine-glowing cluster of facts to memory.

Easy FJ Clues (67–100% correct):

  • H2O / Water (3/3 correct) The easiest Chemistry FJ. When in doubt in a Chemistry Final, H2O is never a bad instinct.
  • Radon (3/3 correct) Clued through its status as a radioactive noble gas found in homes. Contestants handled this well.
  • Arsenic & Zinc (3/3 correct) Appeared together in a single FJ clue. The pairing made it easier, as the two elements were clued through complementary facts.
  • Lead & Gold (2/3 correct) Another paired-element FJ. Lead and gold clued through their Latin names (plumbum and aurum) or alchemical connections.

Moderate FJ Clues (33% correct):

  • Helium (1/3 correct) Clued through its 1868 discovery in the Sun's chromosphere during a solar eclipse, before it was found on Earth. The solar-discovery angle is the key fact.
  • Krypton (1/3 correct) Likely clued through its Greek etymology ("hidden") or its properties. Superman's planet may have caused confusion rather than helping.
  • Europium (1/3 correct) Named for the continent of Europe. A rare earth element (lanthanide) with atomic number 63. Its red phosphorescence is used in euro banknotes as an anti-counterfeiting measure. The geographic-naming angle is the clue path.
  • Polonium (1/3 correct) Named by Marie Curie for her native Poland. Polonium-210 was used to assassinate former Russian spy Alexander Litvinenko in London in 2006. The Poland connection is the essential fact.

FJ Clue Angles

The 15 FJ appearances reveal clear patterns in how the writers construct Chemistry finals:

  1. Etymology and naming origins (most common): Why is it called phosphorus? What element is named for a continent? Which element's name comes from the Greek for "hidden"? This is the dominant FJ angle.

  2. Discovery history: Hennig Brand and phosphorus (1669), helium discovered in the Sun (1868), Marie Curie and polonium/radium. The discoverer + date + method trifecta is classic FJ construction.

  3. Unique physical properties: The only metal liquid at room temperature (mercury), the element discovered in the Sun before Earth (helium), the most radioactive naturally occurring element (radon in homes).

  4. Paired elements: Some FJ clues ask for two elements at once (arsenic & zinc, lead & gold), which actually makes them easier because you get two sets of clues pointing to two answers.

The Stumper Reference

Answer Appearances Wrong % What trips contestants up
Fluorine 5 66.7% "Latin for to flow" contestants don't connect fluere to fluorine
Phosphorus 5 50% Greek "light-bearing" and 0/6 in Final Jeopardy
Radium 6 44.4% Confused with radon, uranium, plutonium; Ra symbol
Zinc 7 42.9% German "prong," galvanizing, brass component
Zirconium 5 41.7% Last alphabetically by symbol (Zr); cubic zirconia
Silver 20 41.7% "Argentum" and Ag symbol; the Latin name curse
Nitrogen 7 41.7% "Most plentiful gas in air" contestants say oxygen
Xenon 5 40% Greek "strange/foreign" obscure noble gas
Tin 10 40% "Stannum" and Sn symbol, another Latin casualty
Polonium 5 40% Marie Curie's homeland (Poland), hard recall

Study Strategy: Priority Order

For maximum return on study time, focus on Chemistry in this order:

Priority 1, The Latin Name Map (highest impact): Memorize all 11 Latin-to-modern element name pairs. This single study action addresses the #1 stumper mechanism and covers silver, tin, lead, mercury, gold, iron, sodium, potassium, antimony, copper, and tungsten, collectively representing over 200 clues.

Priority 2, Noble Gases and Halogens (FJ favorites): Know all six noble gases and their Greek etymologies (especially krypton = "hidden," xenon = "strange," argon = "lazy"). Know the halogens and that fluorine's name means "to flow." These groups account for multiple FJ appearances and high-value stumpers.

Priority 3, Discovery Stories (FJ preparation): Hennig Brand discovering phosphorus from urine (1669). Helium discovered in the Sun's chromosphere (1868). Marie Curie discovering polonium and radium from pitchblende. Mendeleev's periodic table (1869). These are the biographical angles the show uses for Final Jeopardy.

Priority 4, Element Superlatives and Records: Highest melting point (tungsten). Most reactive element (fluorine). Only metal liquid at room temp (mercury; and bromine for nonmetals). Most abundant metal in Earth's crust (aluminum). Most abundant gas in atmosphere (nitrogen, NOT oxygen). Most malleable metal (gold). Best electrical conductor (silver).

Priority 5, Chemistry Concepts: Absolute zero, distillation, oxidation/reduction, the Haber-Bosch process, pH scale, allotropes. These appear less frequently than elements but are reliable $1,000+ fare.

Priority 6, Named Scientists: Lavoisier (father of modern chemistry, named oxygen), Marie Curie (radioactivity, polonium, radium), Mendeleev (periodic table), Hennig Brand (phosphorus), Glenn Seaborg (transuranium elements). Scientists appear most often in FJ and high-value DJ clues.

The 70.5% DJ skew means Chemistry is disproportionately tested at higher difficulty levels. If you are strong in Chemistry, it becomes a powerful weapon in Double Jeopardy and Daily Doubles. If you are weak, the DJ concentration means you will face it repeatedly at the hardest values. There is no middle ground, Chemistry rewards dedicated preparation and punishes casual knowledge.

Gimme Answers

top 50

Memorize these and recognize 34.9% of all Chemistry clues.

#AnswerCountSample Clue
1 mercury 29 Marlin & tilefish may contain high levels of this element, atomic number 80
2 lead 28 "Plumbum" in Latin, Ancient Rome's plumbing was made of this heavy metal
3 carbon 28 Vital for life, it forms more compounds than all the other elements combined
4 silver 22 Let's substitute its symbol into some familiar names & phrases—the Ag surfer; an Ag-tongued devil; hi-yo, Ag! Away!
5 gold 21 It's the precious element whose symbol is found in the middle of the name of Haiti's capital
6 Helium 20 Because it is less dense than air, when we breathe this 2nd-lightest element, it comes out faster & at a higher frequency
7 aluminum 19 The British call this element aluminium
8 hydrogen 18 It has the atomic No. 1 & is the most abundant element in the universe
9 oxygen 18 Add the symbol of this element to "comb" & you get a small jazz band
10 iron 18 The oldest form of iron known, it's popularly used to make gates, fences & railings
11 copper 16 Romans called this Cyprium, the metal of Cyprus
12 sodium 16 Add the symbol of this element to "palm" & you get an incendiary weapon used in bombs
13 platinum 14 Put the symbol for this element after "ine" & you have no aptitude or skill
14 calcium 14 Metallic element essential for strong bones & teeth
15 titanium 13 Lightweight & strong, this element is named for the group that preceded the Olympians in mythology
16 plutonium 13 Bearing the name of a Greek god, this radioactive element was the second transuranium element discovered
17 nitrogen 13 This gas makes up 78% of our air
18 lithium 13 Electric vehicles have brought cash to Chile, a land with large reserves of this lightest metal element, used in batteries
19 iodine 13 In solution, this element that can be extracted from seaweed is used as an antiseptic on cuts & scratches
20 tin 12 Add the symbol for this element to the front of "ow" & you get precipitation
21 sulfur 12 It's used to vulcanize rubber & to make gunpowder
22 neon 12 A Cornhusker chemist might know the symbol of this gas matches the abbreviation of his state
23 silicon 11 After oxygen, this element associated with computer chips is the most common in the earth's crust
24 nickel 11 Iron, cobalt & this silver-white next metal up on the periodic table share similar chemical properties
25 cobalt 11 Alnico magnets are so named because they're alloys of aluminum, nickel & this
26 radon 10 The EPA says this gas seeping into homes causes 21,000 lung cancer deaths a year
27 krypton 10 In the 1960s it was found that this noble gas symbolized Kr can form compounds
28 chlorine 10 World Book says it is "a poisonous, yellowish-green gas with a strong, unpleasant odor", so let's treat our pool with it
29 arsenic 10 Orpiment, formula As 2 S 3 was a longtime aid to painters as a yellow pigment, but not now, due to this, the As
30 uranium 10 2 of the 3 elements named for planets
31 potassium 10 Tack the symbol of this element onto "el" & you get a lodge member
32 zirconium 9 Clap your hands for Martin Klaproth, who discovered uranium & this alphabetically last element
33 zinc 9 Centrum multivitamins say they're "Complete from A to" this element
34 thorium 9 It was identified in 1828 & named for a Norse deity, long before it was found to be a nuclear fuel
35 phosphorus 9 This glow-in-the-dark element is the only one whose name ends in "us"
36 the electrons 9 The British once likened the structure of the atom to a plum pudding & these to the raisins
37 tungsten 8 Metal with highest melting point, it's commonly used in light bulb filaments
38 radium 8 It was discovered in 1898 when 2 scientists in France extracted a minute amount from a ton of pitchblende
39 water 7 Though rarely used, a chemical name of this substance is dihydrogen monoxide
40 Curium 7 This actinide element was discovered in the U.S. but named for a pair of French scientists
41 rust 7 Found in rhubarb, oxalic acid removes calcium from the body & this common oxide from iron
42 polonium 6 Marie Curie named this element for her native land
43 fermium 6 Atomic number 100, this radioactive element is named for the scientist who directed the first controlled fission chain reaction
44 chromium 6 Greek for "color" gives us the name of this metal that will take a high polish
45 argon 6 This element is alphabetically first among the noble gases
46 ammonia 6 The name of this pungent gaseous compound is ultimately derived from the top god of the ancient Egyptians
47 xenon 5 Elements that are gases at room temperature include argon, neon, krypton & this rare "foreign" noble gas used in lighting
48 magnesium 5 You can get wheels for your MG made of this element with the symbol Mg
49 fluorine 5 You get an "F" if you don't know F is this element
50 boron 5 Alphabetically, it's the first element with a single letter as its symbol

Sub-Areas

140
answers to learn
38 Must-Know
20 Should-Know
82 Worth Knowing

Must-Know Answers

These appear 8+ times. Memorize these first.

mercury 29 carbon 29 lead 28 gold 23 silver 22 Helium 21 iron 20 aluminum 19 hydrogen 18 oxygen 18 copper 16 sodium 16 calcium 15 platinum 14 titanium 13 plutonium 13 nitrogen 13 lithium 13 iodine 13 tin 12 sulfur 12 neon 12 silicon 11 nickel 11 cobalt 11 radon 10 krypton 10 chlorine 10 arsenic 10 uranium 10 potassium 10 zirconium 9 zinc 9 thorium 9 phosphorus 9 the electrons 9 tungsten 8 radium 8

Answers by Category

Jump to: Chemistry / Elements | Astronomy / Space | Other | Math / Physics | Biology / Animals | Medicine / Health

Chemistry / Elements

111 answers | 642 clues
Must-Know (28)
carbon 29x 10.3% stumper $683 avg J:9 DJ:20
J $100 1996 A golden yellow when liquid, this element symbolized C is used as a bleach & in making plastics
J $500 1993 Its atomic number, 6, is half its atomic weight, 12
DJ $900 DD 2017 "C" if you can guess this element that follows boron on the periodic table
lead 28x 10.7% stumper $575 avg J:9 DJ:19
J $100 1994 The first commercial use of titanium was as a substitute for this poisonous metal in paint
DJ $600 DD 2003 Painter's colic is a group of symptoms caused by an excess of this element in the body
DJ $1,000 1992 After about 713 million years, half a quantity of uranium-235 turns into this element
gold 23x 4.3% stumper $613 avg J:8 DJ:15
J $100 2000 When the King sang "Wear my ring around your neck", he may have meant one made of this metal, symbolized Au
DJ $600 1993 Placer & lode are the 2 basic methods of mining this precious metal
DJ $1,200 2022 Helen Mirren is trying to recover a portrait by Gustav Klimt in the fact-based movie "Woman in" this
iron 20x $575 avg J:11 DJ:9
J $200 2000 Scientists believe that the Earth's core is primarily made up of this metal, Fe
J $600 2014 Whitman:"You convicts in prison cells—-you sentenced assassins chain'd and handcuff'd with ____"
DJ $1,600 2002 The spleen spends its time taking this element out of the hemoglobin in red blood cells
aluminum 19x 5.3% stumper $632 avg J:12 DJ:7
J $100 1996 In Italian this metal is called alluminio
J $500 1995 Copper, magnesium, manganese & this element form an alloy called duralumin
J $1,000 2008 This ductile, nonradioactive element has an atomic weight of 26.98
hydrogen 18x 5.6% stumper $683 avg J:5 DJ:13
J $200 2010 It's thought that in the early universe, this element made up 75% of all mass
J $600 2003 An alkyl is a hydrocarbon that has lost one of these atoms that has just 1 proton in its nucleus
J $1,000 2003 In the "heavy water" used in nuclear physics, deuterium replaces the usual form of this gas
oxygen 18x 5.6% stumper $583 avg J:7 DJ:11
J $100 1994 Ozone contains 3 atoms of this element per molecule
J $600 2019 This element is usually found as a diatomic molecule making up about 21% of Earth's atmosphere
DJ $1,200 2016 In 1773 Carl Scheele discovered this element first, but Joseph Priestley beat him into print & inhaled the credit
copper 16x 12.5% stumper $788 avg J:8 DJ:8
J $100 1995 This reddish metal is second only to silver as a conductor of electricity
J $500 1996 In moist air this metal, symbol Cu, gradually becomes covered with a green patina
DJ $1,000 DD 1992 All regular U.S. coins minted today contain some of this element
sodium 16x 6.2% stumper $1,031 avg J:2 DJ:14
DJ $200 1997 As indicated by its chemical name, the 2 main elements in table salt are chlorine & this
DJ $600 1987 The element in common table salt that is technically a metal
DJ $1,200 2017 Canned chickpeas can say Na Na, Na Na, Na to canned peas as the latter have less of this element
calcium 15x 13.3% stumper $913 avg J:5 DJ:10
J $200 2002 Nearly all of this element in the body is found in the bones & teeth
J $500 1985 Silver-white metal found in chalk, gypsum, & Wonder Bread
DJ $1,600 2013 Atomic number 20 belongs to this element found in limestone & eggshells
platinum 14x 21.4% stumper $771 avg J:4 DJ:10
J $200 1994 Iridium's chief use is to harden this metal, symbol Pt
J $600 2019 It weighs 21 times as much as an equal volume of water; a CD that sells 2 million units becomes double this
DJ $1,000 1993 Rhodium, iridium & palladium are members of this precious metal's "group"
titanium 13x 30.8% stumper $1,562 avg J:1 DJ:12
DJ $400 1999 It was named after the elder gods of Greece
J $500 1996 In 1795 Martin Klaproth named this metal, now used in the aerospace industry, for its strength
DJ $1,200 2011 Atomic No. 22, this metal was named for some mythological bigwigs
nitrogen 13x 23.1% stumper $969 avg J:2 DJ:11
DJ $200 1985 This gas makes up 78% of our air
DJ $600 2000 This element makes up about 78% of normal dry air by volume
DJ $1,200 2009 Ammonia: ____H 3
lithium 13x 23.1% stumper $1,108 avg J:1 DJ:12
DJ $400 2022 A mood stabilizer, it comes in at a helpful No. 3 (but it didn't crack the Top 40 for Nirvana)
J $500 1995 This lightest metal tarnishes rapidly when exposed to air
DJ $1,000 1991 A compound of this lightest metal has been found effective in treating manic depressives
iodine 13x 38.5% stumper $746 avg J:3 DJ:10
DJ $200 1993 In Japan seaweed is a major source of this element identified by the symbol I
J $600 2013 In solution, this element that can be extracted from seaweed is used as an antiseptic on cuts & scratches
J $1,000 2019 DN
tin 12x 16.7% stumper $758 avg J:5 DJ:7
J $200 1991 The name of this element can precede horn, can & Lizzie
DJ $600 1997 The pewter used to make bowls & tea services is at least 90% this metal
DJ $1,000 1991 Sometimes used for fine tableware, pewter consists mainly of this metal
silicon 11x $1,673 avg J:4 DJ:7
J $200 1986 Member of carbon family so vital to electronics a high-tech "valley" bears its name
J $600 2004 In the electronics industry, this element symbolized Si, is made into N- & P-types of semiconductors
J $1,000 DD 2015 The 2 most abundant elements in Earth's crust are oxygen & this one used in making electronic circuits
nickel 11x 27.3% stumper $891 avg J:3 DJ:8
J $200 2007 Atomic number 28; if you don't know 1 lb. of pure this can be drawn into a wire 80 mi. long, you're not worth a plugged one
DJ $1,000 1993 This metal is joined with cadmium to make rechargeable batteries
J $200 1995 Most meteorites contain this element symbolized Ni
cobalt 11x $909 avg J:6 DJ:5
J $200 1996 Symbolized Co, it's used in paints & varnishes & is essential for a good diet
DJ $800 1996 Making up the iron family on the periodic table are iron, nickel & this blue-tinged metal
J $1,000 2009 A U.S. nuclear weapon using this element, Co, has been termed a doomsday device, as it would wipe out life on Earth
radon 10x $1,156 avg J:1 DJ:8 FJ:1
DJ $400 1996 In 1993 the EPA advised that people buying a house should check for this gas, symbol Rn
DJ $800 2010 Rn: Ms. Chong might be able to help you with this one
DJ $1,000 2000 Radium comes from radius, the Latin for "ray"; this element's name comes from radium
chlorine 10x 10.0% stumper $590 avg J:3 DJ:7
J $200 2012 Atomic number 17, it's poisonous, smells bad & causes irritation to the nose, lungs & throat; put some in my pool, please!
DJ $800 2008 Although it's a poisonous gas, this element is used to purify drinking water & swimming pools
DJ $1,200 2011 This element, atomic no. 17, is used as a bleach
potassium 10x $700 avg J:2 DJ:8
DJ $200 1990 Not only is this element found in potash, it's named for it
DJ $800 2020 An essential nutrient, this element, symbol K, is in bananas, lima beans & avocados
DJ $1,200 2006 Tack the symbol of this element onto "el" & you get a lodge member
zirconium 9x 22.2% stumper $978 avg J:3 DJ:6
DJ $200 1992 This element was discovered in 1789 in the mineral zircon
J $600 2015 After zinc
DJ $1,000 DD 2009 Clap your hands for Martin Klaproth, who discovered uranium & this alphabetically last element
thorium 9x $1,356 avg J:1 DJ:8
J $400 2013 This element's name, from the Norse god of thunder, was first erroneously applied to yttrium phosphate
DJ $1,000 1991 Used in some camping lanterns, it was named after the Norse god of thunder
DJ $400 2000 In 1828 a Norse god thundered onto the periodic table in the name of this element, No. 90
phosphorus 9x 57.1% stumper $943 avg J:4 DJ:3 FJ:2
J $400 1995 Found in a compound used in soft drinks, this element, P, ignites in air
DJ $600 1999 The red form of this element that glows in the dark is used in the production of matches
J $1,000 2011 This element that's "ph" balanced (it has 2 of them) ends with the name of an Egyptian falcon god
the electrons 9x 11.1% stumper $778 avg J:3 DJ:6
DJ $400 2002 In 1916 G. N. Lewis proposed that atoms in a molecule bond by sharing a pair of these particles
J $600 2022 Transition metals like nickel or iron have "valence" these, which like to bond
DJ $1,200 2005 The configuration of these in an atom is usually given for the ground state, not the excited state
tungsten 8x 12.5% stumper $1,000 avg J:4 DJ:4
J $400 1996 California & Colorado are the leading U.S. producers of this metal also called wolfram
J $500 1994 The metal known as Wolfram in Germany & other European countries is called this in the United States
J $1,000 2019 ( Jimmy of the Clue Crew shows a lightbulb on the monitor.) Because it has the highest melting point of all metals, this element was long used as a filament in incandescent lightbulbs
radium 8x 28.6% stumper $471 avg J:4 DJ:3 FJ:1
DJ $200 1999 You can isolate about 1 gram of this element, Ra, out of several tons of pitchblende
J $500 1986 Radon is the gaseous emanation from this element
J $1,000 2013 Its 35 known isotopes are all radioactive
Should-Know (19)
water 7x 14.3% stumper $615 avg J:2 DJ:5
DJ $200 1996 By definition, an anhydrous compound doesn't have this in it
DJ $1,200 2011 A chemical known as an anhydride is one that removes this from substances
J $300 1986 Since oxygen is the most abundant element on Earth, this is the most abundant compound
rust 7x 14.3% stumper $543 avg J:1 DJ:6
DJ $400 1988 Found in rhubarb, oxalic acid removes calcium from the body & this common oxide from iron
J $600 2002 Wet steel wool in a jar helps demonstrate the formation of this; so does an old car
DJ $1,200 2024 Fe 2 O 3 is the chemical formula for this 4-letter concern
argon 7x $1,000 avg J:3 DJ:2 FJ:2
J $600 2025 Of the 3 main gases that compose most of the Earth's atmosphere, this noble one makes up about 1%
J $1,000 2022 The Constitution is preserved in a case containing this noble gas, atomic No. 18; its inertness helps stop organic decay
FJ 1992 Alphabetically the first among gases, it's the third most abundant gas in the air
polonium 6x 20.0% stumper $980 avg DJ:5 FJ:1
DJ $800 DD 1996 Marie Curie named this rare element for the country where she was born
DJ $1,000 1997 Named for Marie Curie's native country, it was the 1st element discovered by means of its radioactivity
FJ 2009 Once called radium F, this element was named for the homeland of one of its discoverers
fermium 6x 33.3% stumper $2,600 avg DJ:6
DJ $1,000 1996 Einsteinium & this element, symbol Fm, were first produced in a 1952 thermonuclear explosion
DJ $1,000 1991 Just breaking into the top 100 is this element named after an Italian physicist
DJ $1,600 2015 No. 100 on the periodic table is this artificially created element, named for an Italian-born physicist
chromium 6x $1,083 avg J:1 DJ:5
J $100 1993 Chrome is the shorter name of this metal, or any of various alloys containing it
DJ $1,000 1996 This element that hardens steel has been used to plate auto bumpers & trim
DJ $400 2003 Car bumpers are usually coated with this glossy metal that's corrosion-resistant
ammonia 6x 60.0% stumper $1,000 avg DJ:5 FJ:1
DJ $400 2014 The name of this gas comes from Amun, a temple in Libya near where its salts were obtained
DJ $1,000 1990 Fritz Haber is famous for inventing a process to make this smelly gas, NH3, synthetically
FJ 2023 The name of this pungent gaseous compound is ultimately derived from the top god of the ancient Egyptians
the noble gases 6x $833 avg J:1 DJ:5
DJ $400 2006 The 6 "inert" elements occur naturally primarily in this state of matter
DJ $800 2019 Currently, the only elements that oxygen cannot create an oxide with are the lightest 4 gases in this group
DJ $1,200 2025 In the right column of the periodic table, nonmetals in the group known by this name are the least reactive of all the elements
xenon 5x 25.0% stumper $875 avg J:3 DJ:1 FJ:1
J $400 2008 The Kennedy Space Center uses this gas, atomic No. 54 & no warrior princess, in high-intensity lights for night landings
J $500 1994 On the periodic table, Xe marks the spot for this element
J $1,000 2007 ( Cheryl of the Clue Crew reports from Princeton University.) The hull thruster, a plasma-based propulsion system for space, burns this element that glows in some luxury cars' headlights
magnesium 5x $860 avg J:1 DJ:4
DJ $200 1991 In the United States, seawater extraction is the source of much of this light metal, symbol Mg
J $500 1996 This metal 2/3 the weight of aluminum burns with a brilliant white light & is used in flares
DJ $2,000 2011 ( Alex walks along the shore of the Dead Sea in Israel with mud all over his face.) For hundreds of years people have believed in the rejuvenating qualities of the Dead Sea's black mud; among its many components this element, symbol Mg, said to remov...
fluorine 5x 60.0% stumper $600 avg J:1 DJ:4
DJ $400 2011 It's from the Latin for "to flow"
J $600 2007 Atomic number 9, it's a trace element in the body, notably in the teeth
DJ $400 1985 In 1945, Grand Rapids, MI & Newburgh, NY became 1st U.S. cities to add it to their water
boron 5x 20.0% stumper $440 avg J:2 DJ:3
J $200 2013 2 substances, borax & carbon, give us the name of this element used in nuclear control rods
J $600 2003 Though not identified until 1808, it still managed to get a low single-letter abbreviation, B
DJ $1,000 DD 2024 Alphabetically, it's the first element with a single letter as its symbol
steel 5x $380 avg J:1 DJ:4
J $100 1994 The "stainless" type of this alloy contains at least 12% chromium
DJ $800 2008 ( Cheryl of the Clue Crew uses a magnet on a beverage can and a food can.) In separating recyclables, a magnet is used because it will not attract aluminum, but will attract this metal, the main constituent of what we call tin cans
DJ $200 1997 The addition of chromium to this alloy makes it extra strong & "stainless"
Robert Bunsen 5x $880 avg J:1 DJ:4
J $200 2003 This man whose name is on a laboratory burner invented a carbon-zinc electric cell
DJ $1,600 2013 Cesium was discovered in 1860 by Gustav Kirchhoff & this "burner" guy while analyzing mineral water
DJ $200 1996 Cesium & rubidium were discovered by Gustav Kirchhoff & this man famous for his burner
sulphur 4x $800 avg J:2 DJ:2
J $200 1997 Brimstone is another name for this light yellow nonmetallic element
J $1,000 2014 Milton: "With ever-burning ____ unconsum'd, such place eternal justice has prepar'd"
DJ $400 1993 In ancient times, this yellow element was burned to fumigate homes
salt 4x $650 avg DJ:4
DJ $400 1984 Common kitchen substance known chemically as sodium chloride
DJ $600 1998 Brine is defined as water containing this in concentrated form
DJ $800 2006 Bittern, a source of bromides & iodides, is the solution left after this has been crystallized from seawater
distillation 4x $1,750 avg DJ:4
DJ $800 2002 Boiling a liquid, condensing the vapor, boilng that liquid, etc. is called the "fractional" type of this process
DJ $1,000 1991 Used for purification, this is the process of boiling a liquid & condensing the vapor
DJ $1,600 2023 "D" is for this chemical process seen here in which a liquid is turned to a vapor then condensed back into a liquid
acids 4x $1,300 avg J:1 DJ:3
DJ $200 2000 Among these, nitric & hydrochloric are "strong", meaning they ionize readily in water
J $800 2002 Use the dye from boiled red cabbage to tell alkalis apart from these, like lemon juice
DJ $4,000 DD 2002 In 1923 Bronsted & Lowry figured out that these substances donate protons to bases
the periodic table 4x $350 avg J:1 DJ:3
J $400 1988 On this famous chart, the vertical columns are groups & the horizontal rows, periods
DJ $600 1984 Chart of elements arranged by atomic number
DJ $200 1985 These are often arranged according to atomic number
Worth Knowing (64)

Astronomy / Space

16 answers | 169 clues
Must-Know (10)
mercury 29x 7.1% stumper $650 avg J:15 DJ:13 FJ:1
J $100 1993 This liquid metal is used to make a red paint pigment called vermilion
J $600 2011 This liquid metal is 13.6 times heavier than an equal volume of water
J $1,000 DD 2004 Its symbol Hg comes from the Latin hydrargyrum, "watery silver"
silver 22x 27.3% stumper $618 avg J:7 DJ:15
J $200 2014 Countee Cullen: "Some are teethed on a ____ spoon, with the stars strung for a rattle"
DJ $600 1998 Copper is the best low-cost conductor of electricity but this metal is the best conductor overall
DJ $1,200 2006 ( Kelly of the Clue Crew reports with some textiles from NC State University in Raleigh, NC.) North Carolina State University is developing shirts lined with transmitters made of this element, symbol Ag, that may one day monitor your vital signs
Helium 21x $555 avg J:4 DJ:16 FJ:1
J $200 2013 Because it is less dense than air, when we breathe this 2nd-lightest element, it comes out faster & at a higher frequency
J $600 2007 Fly high with this colorless, odorless & tasteless gas, atomic no. 2
DJ $1,000 1984 U.S. & Canada produce almost entire world supply of this lightest inert gas
plutonium 13x 38.5% stumper $954 avg J:5 DJ:8
J $200 2015 After platinum
J $500 1994 After neptunium, this radioactive metal was the next transuranium element discovered
J $1,000 2012 Glenn Seaborg & colleagues discovered this nuclear weapon ingredient on Feb. 23, 1941
sulfur 12x 16.7% stumper $825 avg J:5 DJ:7
J $400 2011 This element, No. 16 on the periodic table, has a pelt at the end of its name
J $500 1991 It's used in gunpowder & to vulcanize rubber
J $1,000 2002 By putting silver & aluminum together in a solution, you can remove tarnish, caused by this element with the symbol S
neon 12x 16.7% stumper $825 avg J:4 DJ:8
J $200 1994 Mercury added to this gaseous element will make it glow blue instead of orange-red
DJ $600 2001 A Cornhusker chemist might know the symbol of this gas matches the abbreviation of his state
DJ $900 DD 2000 The names of neodymium & this element are both traced back to the Greek neo, "new"
krypton 10x 11.1% stumper $556 avg J:4 DJ:5 FJ:1
J $200 2003 Superman could tell you this odorless, colorless gas bears atomic No. 36
J $600 2022 Daniel Wallace's "Supergirl" is subtitled "Daughter of" this planet
DJ $1,200 DD 1994 The name of this noble gas is from a Greek word for "hidden"
arsenic 10x 10.0% stumper $1,160 avg J:4 DJ:6
J $100 1997 In the title of an old comedy, it's paired with "Old Lace"
J $500 1994 This metal found in rat poisons can be detected in hair or fingernails
DJ $1,200 2004 In 1991 Zachary Taylor's body was exhumed to determine if he'd been poisoned by this element
uranium 10x 10.0% stumper $580 avg J:4 DJ:6
J $200 2015 Pre-reactor use, this-235 must be separated from this-238, which is more plentiful but doesn't fission easily
DJ $600 1992 In 1896 future Nobel winner Antoine Henri Becquerel discovered this element was radioactive
J $1,000 2013 Discovered in Colorado in the 1950s, coffinite is an ore that is more than 60% this radioactive metal
zinc 9x 55.6% stumper $1,044 avg J:3 DJ:6
J $500 2000 This metal is used to galvanize steel to prevent rusting
J $1,000 2002 This element used to galvanize steel is also used in lozenges to treat a cold—go figure!
J $500 1994 In brass, less copper & more of this metal will make it appear gold
Should-Know (1)
Curium 7x $1,086 avg J:1 DJ:6
J $400 2025 Named for a married couple, it's used to power X-ray spectrometers in the Mars rovers
DJ $800 2022 It's named for 2 French physicists & one isotope has a half-life of 15.6 million years
DJ $1,000 1997 This synthetic radioactive element was named for the discoverers of radium
Worth Knowing (5)

Math / Physics

2 answers | 6 clues
Worth Knowing (2)

Biology / Animals

3 answers | 6 clues
Worth Knowing (3)

Medicine / Health

1 answers | 3 clues
Worth Knowing (1)
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