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Chemical Elements, by Atomic Number Quiz

How well do you know the chemical elements, by atomic number? Floored turns the ranking into a building: floor 1 is the top of the list. We name a floor, you guess what's on it, and the lift rides to whatever you picked so you know to go higher or lower.

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You get a few guesses per floor. Land it on your first guess for 10 points; a near miss still scores. After the elements round, four more lists keep the ride going.

Show the full ranking (54)
  1. Hydrogen H, 1.008 u
    About three-quarters of the normal matter in the universe, by mass, is hydrogen.
  2. Helium He, 4.003 u
    It was found in the Sun's spectrum in 1868, decades before it was found on Earth.
  3. Lithium Li, 7.0 u
    It's so light it floats on water, and even on oil.
  4. Beryllium Be, 9.012 u
    Emeralds and aquamarines are both gem forms of the beryllium mineral beryl.
  5. Boron B, 10.81 u
    It's the ingredient that makes borosilicate glass, like classic Pyrex, heat resistant.
  6. Carbon C, 12.011 u
    Diamonds and pencil graphite are both made of pure carbon.
  7. Nitrogen N, 14.007 u
    It was once called 'azote', meaning 'lifeless', because animals suffocated in it.
  8. Oxygen O, 15.999 u
    Liquid oxygen is pale blue and is attracted to magnets.
  9. Fluorine F, 18.998 u
    It's the most reactive element; even glass and water burn in it.
  10. Neon Ne, 20.180 u
    Real neon signs glow red-orange; other 'neon' colors come from different gases.
  11. Sodium Na, 22.990 u
    Pure sodium is soft enough to cut with a knife and reacts violently with water.
  12. Magnesium Mg, 24.305 u
    It burns with a dazzling white light that early photographers used as a flash.
  13. Aluminum Al, 26.982 u
    It was once more prized than gold; Napoleon III saved aluminum cutlery for honored guests.
  14. Silicon Si, 28.085 u
    Silicon Valley is named after it, thanks to the silicon in computer chips.
  15. Phosphorus P, 30.974 u
    It was discovered in 1669 by an alchemist boiling down urine.
  16. Sulfur S, 32.07 u
    'Brimstone', as in fire and brimstone, is an old name for sulfur.
  17. Chlorine Cl, 35.45 u
    It was used as a chemical weapon at Ypres in 1915.
  18. Argon Ar, 39.9 u
    Its name comes from the Greek for 'lazy', because it barely reacts with anything.
  19. Potassium K, 39.098 u
    Its symbol K comes from 'kalium', from an Arabic word for plant ashes.
  20. Calcium Ca, 40.08 u
    It's the most abundant metal in the human body.
  21. Scandium Sc, 44.956 u
    It's named after Scandinavia, where it was discovered.
  22. Titanium Ti, 47.867 u
    It's named after the Titans of Greek mythology.
  23. Vanadium V, 50.941 u
    It's named after Vanadis, another name for the Norse goddess Freyja.
  24. Chromium Cr, 51.996 u
    Traces of it give rubies their red color and emeralds their green.
  25. Manganese Mn, 54.938 u
    Prehistoric cave painters used manganese oxides as black pigment.
  26. Iron Fe, 55.84 u
    Earth's core is thought to be made mostly of iron, with some nickel.
  27. Cobalt Co, 58.933 u
    Its name comes from 'kobold', a goblin German miners blamed for troublesome ore.
  28. Nickel Ni, 58.693 u
    The US five-cent 'nickel' is actually 75% copper.
  29. Copper Cu, 63.55 u
    The Statue of Liberty is green because its copper skin has weathered.
  30. Zinc Zn, 65.4 u
    Brass is an alloy of copper and zinc.
  31. Gallium Ga, 69.723 u
    It melts at about 30 degrees Celsius, so it can melt in your hand.
  32. Germanium Ge, 72.63 u
    Mendeleev predicted it as 'eka-silicon' about 15 years before it was found.
  33. Arsenic As, 74.922 u
    Tests on locks of Napoleon's hair found unusually high levels of arsenic.
  34. Selenium Se, 78.97 u
    It's named after Selene, the Greek goddess of the Moon.
  35. Bromine Br, 79.90 u
    It's one of only two elements that are liquid at room temperature.
  36. Krypton Kr, 83.80 u
    From 1960 to 1983, the meter was officially defined using light from krypton-86.
  37. Rubidium Rb, 85.468 u
    It was discovered by its red spectral lines; its name means 'deep red'.
  38. Strontium Sr, 87.62 u
    It gives fireworks their bright red color.
  39. Yttrium Y, 88.906 u
    It's named after Ytterby, a Swedish village that lent its name to four elements.
  40. Zirconium Zr, 91.22 u
    Cubic zirconia, the popular diamond lookalike, is made from zirconium oxide.
  41. Niobium Nb, 92.906 u
    It's named after Niobe, daughter of Tantalus, because it's so similar to tantalum.
  42. Molybdenum Mo, 95.95 u
    Its name comes from the Greek for lead, because its ore was confused with lead.
  43. Technetium Tc, 96.906 u (Tc-97)
    It was the first element made artificially, and none of its isotopes are stable.
  44. Ruthenium Ru, 101.1 u
    It's named after Ruthenia, a Latin name for Russia.
  45. Rhodium Rh, 102.906 u
    It's one of the rarest and most expensive precious metals.
  46. Palladium Pd, 106.42 u
    It's named after the asteroid Pallas, discovered in 1802, the same year as the element.
  47. Silver Ag, 107.868 u
    It conducts electricity better than any other element.
  48. Cadmium Cd, 112.41 u
    Cadmium pigments gave artists like Monet vivid yellows and oranges.
  49. Indium In, 114.818 u
    A bar of indium makes a high-pitched 'cry' when you bend it.
  50. Tin Sn, 118.71 u
    Below about 13 degrees Celsius, tin can slowly crumble into gray powder called 'tin pest'.
  51. Antimony Sb, 121.760 u
    Ancient Egyptians used antimony sulfide as kohl eyeliner.
  52. Tellurium Te, 127.6 u
    Exposure to it can leave people with garlic-smelling breath for weeks.
  53. Iodine I, 126.904 u
    Its vapor is violet, and its name comes from the Greek word for violet.
  54. Xenon Xe, 131.29 u
    It's the propellant in the ion thrusters of spacecraft like NASA's Dawn.

Source: PubChem Periodic Table (NCBI) · as of 2026-10

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