Appendix K: The Chemical Elements
The Chemical Elements | ||||
---|---|---|---|---|
Element | Symbol | Atomic Number | Atomic Weight1 | Percentage of Naturally Occurring Elements in the Universe |
Hydrogen | H | 1 | 1.008 | 75 |
Helium | He | 2 | 4.003 | 23 |
Lithium | Li | 3 | 6.94 | 6 × 10−7 |
Beryllium | Be | 4 | 9.012 | 1 × 10−7 |
Boron | B | 5 | 10.821 | 1 × 10−7 |
Carbon | C | 6 | 12.011 | 0.5 |
Nitrogen | N | 7 | 14.007 | 0.1 |
Oxygen | O | 8 | 15.999 | 1 |
Fluorine | F | 9 | 18.998 | 4 × 10−5 |
Neon | Ne | 10 | 20.180 | 0.13 |
Sodium | Na | 11 | 22.990 | 0.002 |
Magnesium | Mg | 12 | 24.305 | 0.06 |
Aluminum | Al | 13 | 26.982 | 0.005 |
Silicon | Si | 14 | 28.085 | 0.07 |
Phosphorus | P | 15 | 30.974 | 7 × 10−4 |
Sulfur | S | 16 | 32.06 | 0.05 |
Chlorine | Cl | 17 | 35.45 | 1 × 10−4 |
Argon | Ar | 18 | 39.948 | 0.02 |
Potassium | K | 19 | 39.098 | 3 × 10−4 |
Calcium | Ca | 20 | 40.078 | 0.007 |
Scandium | Sc | 21 | 44.956 | 3 × 10−6 |
Titanium | Ti | 22 | 47.867 | 3 × 10−4 |
Vanadium | V | 23 | 50.942 | 3 × 10−4 |
Chromium | Cr | 24 | 51.996 | 0.0015 |
Manganese | Mn | 25 | 54.938 | 8 × 10−4 |
Iron | Fe | 26 | 55.845 | 0.11 |
Cobalt | Co | 27 | 58.933 | 3 × 10−4 |
Nickel | Ni | 28 | 58.693 | 0.006 |
Copper | Cu | 29 | 63.546 | 6 × 10−6 |
Zinc | Zn | 30 | 65.38 | 3 × 10−5 |
Gallium | Ga | 31 | 69.723 | 1 × 10−6 |
Germanium | Ge | 32 | 72.630 | 2 × 10−5 |
Arsenic | As | 33 | 74.922 | 8 × 10−7 |
Selenium | Se | 34 | 78.971 | 3 × 10−6 |
Bromine | Br | 35 | 79.904 | 7 × 10−7 |
Krypton | Kr | 36 | 83.798 | 4 × 10−6 |
Rubidium | Rb | 37 | 85.468 | 1 × 10−6 |
’Strontium | Sr | 38 | 87.62 | 4 × 10−6 |
Yttrium | Y | 39 | 88.906 | 7 × 10−7 |
Zirconium | Zr | 40 | 91.224 | 5 × 10−6 |
Niobium | Nb | 41 | 92.906 | 2 × 10−7 |
Molybdenum | Mo | 42 | 95.95 | 5 × 10−7 |
Technetium | Tc | 43 | (98) | — |
Ruthenium | Ru | 44 | 101.07 | 4 × 10−7 |
Rhodium | Rh | 45 | 102.906 | 6 × 10−8 |
Palladium | Pd | 46 | 106.42 | 2 × 10−7 |
Silver | Ag | 47 | 107.868 | 6 × 10−8 |
Cadmium | Cd | 48 | 112.414 | 2 × 10−7 |
Indium | In | 49 | 114.818 | 3 × 10−8 |
Tin | Sn | 50 | 118.710 | 4 × 10−7 |
Antimony | Sb | 51 | 121.760 | 4 × 10−8 |
Tellurium | Te | 52 | 127.60 | 9 × 10−7 |
Iodine | I | 53 | 126.904 | 1 × 10−7 |
Xenon | Xe | 54 | 131.293 | 1 × 10−6 |
Cesium | Cs | 55 | 132.905 | 8 × 10−8 |
Barium | Ba | 56 | 137.327 | 1 × 10−6 |
Lanthanum | La | 57 | 138.905 | 2 × 10−7 |
Cerium | Ce | 58 | 140.116 | 1 × 10−6 |
Praseodymium | Pr | 59 | 140.907 | 2 × 10−7 |
Neodymium | Nd | 60 | 144.242 | 1 × 10−6 |
Promethium | Pm | 61 | (145) | — |
Samarium | Sm | 62 | 150.36 | 5 × 10−7 |
Europium | Eu | 63 | 151.964 | 5 × 10−8 |
Gadolinium | Gd | 64 | 157.25 | 2 × 10−7 |
Terbium | Tb | 65 | 158.925 | 5 × 10−8 |
Dysprosium | Dy | 66 | 162.500 | 2 × 10−7 |
Holmium | Ho | 67 | 164.930 | 5 × 10−8 |
Erbium | Er | 68 | 167.259 | 2 × 10−7 |
Thulium | Tm | 69 | 168.934 | 1 × 10−8 |
Ytterbium | Yb | 70 | 173.054 | 2 × 10−7 |
Lutetium | Lu | 71 | 174.967 | 1 × 10−8 |
Hafnium | Hf | 72 | 178.49 | 7 × 10−8 |
Tantalum | Ta | 73 | 180.948 | 8 × 10−9 |
Tungsten | W | 74 | 183.84 | 5 × 10−8 |
Rhenium | Re | 75 | 186.207 | 2 × 10−8 |
Osmium | Os | 76 | 190.23 | 3 × 10−7 |
Iridium | Ir | 77 | 192.217 | 2 × 10−7 |
Platinum | Pt | 78 | 195.084 | 5 × 10−7 |
Gold | Au | 79 | 196.967 | 6 × 10−8 |
Mercury | Hg | 80 | 200.592 | 1 × 10−7 |
Thallium | TI | 81 | 204.38 | 5 × 10−8 |
Lead | Pb | 82 | 207.2 | 1 × 10−6 |
Bismuth | Bi | 83 | 208.980 | 7 × 10−8 |
Polonium | Po | 84 | (209) | — |
Astatine | At | 85 | (210) | — |
Radon | Rn | 86 | (222) | — |
Francium | Fr | 87 | (223) | — |
Radium | Ra | 88 | (226) | — |
Actinium | Ac | 89 | (227) | — |
Thorium | Th | 90 | 232.038 | 4 × 10−8 |
Protactinium | Pa | 91 | 231.036 | — |
Uranium | U | 92 | 238.029 | 2 × 10−8 |
Neptunium | Np | 93 | (237) | — |
Plutonium | Pu | 94 | (244) | — |
Americium | Am | 95 | (243) | — |
Curium | Cm | 96 | (247) | — |
Berkelium | Bk | 97 | (247) | — |
Californium | Cf | 98 | (251) | — |
Einsteinium | Es | 99 | (252) | — |
Fermium | Fm | 100 | (257) | — |
Mendelevium | Md | 101 | (258) | — |
Nobelium | No | 102 | (259) | — |
Lawrencium | Lr | 103 | (262) | — |
Rutherfordium | Rf | 104 | (267) | — |
Dubnium | Db | 105 | (268) | — |
Seaborgium | Sg | 106 | (271) | — |
Bohrium | Bh | 107 | (272) | — |
Hassium | Hs | 108 | (270) | — |
Meitnerium | Mt | 109 | (276) | — |
Darmstadtium | Ds | 110 | (281) | — |
Roentgenium | Rg | 111 | (280) | — |
Copernicium | Cn | 112 | (285) | — |
Ununtrium | Uut | 113 | (284) | — |
Flerovium | Fl | 114 | (289) | — |
Ununpentium | Uup | 115 | (288) | — |
Livermorium | Lv | 116 | (293) | — |
Ununseptium | Uus | 117 | (294) | — |
Ununoctium | Uuo | 118 | (294) | — |
Note: Some of the newest elements near the bottom of the table have suggested names that are still under review, and those names are not yet listed here. For example, Tennessine is suggested for element 117, after the state where the Oak Ridge National Laboratory is located.
Footnotes
- 1 Where mean atomic weights have not been well determined, the atomic mass numbers of the most stable isotopes are given in parentheses.