The oxidation state tells how many valence electrons an atom accepts (negative number) or donates (positive number) to form a chemical bond.
The most stable oxidation state is one that fills or half-fills an atom’s electron shell. But, atoms of most elements display multiple oxidation states! Remember, shells don’t neatly stack on top of each other, so valence (and oxidation state) are not necessarily the same as the total number of electrons in the outer shell.
This table lists the most common oxidation states of all 118 elements. The most common valences are in BOLD. Values in italics are predicted theoretical values.
| NUMBER | SYMBOL | ELEMENT | OXIDATION STATE |
| 1 | H | Hydrogen | 1, 0, -1 |
| 2 | He | Helium | 0 |
| 3 | Li | Lithium | 1, -1 |
| 4 | Be | Beryllium | 2 |
| 5 | B | Boron | 3, 2, 1 |
| 6 | C | Carbon | 4, 3, 2, 1, -1, -2, -4 |
| 7 | N | Nitrogen | 5, 4, 3, 2, 1, 0, -1, -2, -3 |
| 8 | O | Oxygen | 2, 1, 0, -1, -2 |
| 9 | F | Fluorine | 0, -1 |
| 10 | Ne | Neon | 0 |
| 11 | Na | Sodium | 1, -1 |
| 12 | Mg | Magnesium | 2 |
| 13 | Al | Aluminum | 3, 1 |
| 14 | Si | Silicon | 4, 3, 2, 1, -1, -2, -4 |
| 15 | P | Phosphorus | 5, 4, 3, 2, 1, 0, -1, -2, -3 |
| 16 | S | Sulfur | 6, 5, 4, 3, 2, 1, 0, -1, -2 |
| 17 | Cl | Chlorine | 6, 5, 4, 3, 2, 1, 0, -1, -2 |
| 18 | Ar | Argon | 0 |
| 19 | K | Potassium | 1, -1 |
| 20 | Ca | Calcium | 2 |
| 21 | Sc | Scandium | 3, 2, 1 |
| 22 | Ti | Titanium | 4, 3, 2, 0, -1, -2 |
| 23 | V | Vanadium | 5, 4, 3, 2, 1, 0, -1, -2 |
| 24 | Cr | Chromium | 6, 5, 4, 3, 2, 1, 0, -1, -2, -3, -4 |
| 25 | Mn | Manganese | 7, 6, 5, 4, 3, 2, 1, 0, -1, -2, -3 |
| 26 | Fe | Iron | 6, 5, 4, 3, 2, 1, 0, -1, -2 |
| 27 | Co | Cobalt | 5, 4, 3, 2, 1, 0, -1 |
| 28 | Ni | Nickel | 6, 4, 3, 2, 1, 0, -1 |
| 29 | Cu | Copper | 4, 3, 2, 1, 0 |
| 30 | Zn | Zinc | 2, 1, 0 |
| 31 | Ga | Gallium | 3, 2, 1 |
| 32 | Ge | Germanium | 4, 3, 2, 1 |
| 33 | As | Arsenic | 5, 3, 2, -3 |
| 34 | Se | Selenium | 6, 4, 2, 1, -2 |
| 35 | Br | Bromine | 7, 5, 4, 3, 1, 0, -1 |
| 36 | Kr | Krypton | 2, 0 |
| 37 | Rb | Rubidium | 1, -1 |
| 38 | Sr | Strontium | 2 |
| 39 | Y | Yttrium | 3, 2 |
| 40 | Zr | Zirconium | 4, 3, 2, 1, 0, -2 |
| 41 | Nb | Niobium | 5, 4, 3, 2, 1, 0, -1, -3 |
| 42 | Mo | Molybdenum | 6, 5, 4, 3, 2, 1, 0, -1, -2 |
| 43 | Tc | Technetium | 7, 6, 5, 4, 3, 2, 1, 0, -1, -3 |
| 44 | Ru | Ruthenium | 8, 7, 6, 5, 4, 3, 2, 1, 0, -2 |
| 45 | Rh | Rhodium | 6, 5, 4, 3, 2, 1, 0, -1 |
| 46 | Pd | Palladium | 4, 2, 0 |
| 47 | Ag | Silver | 3, 2, 1, 0 |
| 48 | Cd | Cadmium | 2, 1 |
| 49 | In | Indium | 3, 2, 1 |
| 50 | Sn | Tin | 4, 2, -4 |
| 51 | Sb | Antimony | 5, 3, -3 |
| 52 | Te | Tellurium | 6, 5, 4, 2, 1, -2 |
| 53 | I | Iodine | 7, 5, 3, 1, 0, -1 |
| 54 | Xe | Xenon | 8, 6, 4, 3, 2, 0 |
| 55 | Cs | Cesium | 1, -1 |
| 56 | Ba | Barium | 2 |
| 57 | La | Lanthanum | 3, 2 |
| 58 | Ce | Cerium | 4, 3, 2 |
| 59 | Pr | Praseodymium | 4, 3, 2 |
| 60 | Nd | Neodymium | 4, 3, 2 |
| 61 | Pm | Promethium | 3 |
| 62 | Sm | Samarium | 3, 2 |
| 63 | Eu | Europium | 3, 2 |
| 64 | Gd | Gadolinium | 3, 2, 1 |
| 65 | Tb | Terbium | 4, 3, 1 |
| 66 | Dy | Dysprosium | 4, 3, 2 |
| 67 | Ho | Holmium | 3, 2 |
| 68 | Er | Erbium | 3 |
| 69 | Tm | Thulium | 3, 2 |
| 70 | Yb | Ytterbium | 3, 2 |
| 71 | Lu | Lutetium | 3 |
| 72 | Hf | Hafnium | 4, 3, 2, 1 |
| 73 | Ta | Tantalum | 5, 4, 3, 2, 1, -1, -3 |
| 74 | W | Tungsten | 6, 5, 4, 3, 2, 1, 0, -1, -2, -4 |
| 75 | Re | Rhenium | 7, 6, 5, 4, 3, 2, 1, 0, -1, -3 |
| 76 | Os | Osmium | 8, 7, 6, 5, 4, 3, 2, 1, 0, -2 |
| 77 | Ir | Iridium | 6, 5, 4, 3, 2, 1, 0, -1 |
| 78 | Pt | Platinum | 6, 5, 4, 2, 0 |
| 79 | Au | Gold | 7, 5, 3, 2, 1, 0, -1 |
| 80 | Hg | Mercury | 2, 1 |
| 81 | Tl | Thallium | 3, 1 |
| 82 | Pb | Lead | 4, 2 |
| 83 | Bi | Bismuth | 5, 3, 1, -3 |
| 84 | Po | Polonium | 6, 4, 2, -2 |
| 85 | At | Astatine | 7, 5, 3, 1, -1 |
| 86 | Rn | Radon | 2, 0 |
| 87 | Fr | Francium | 1 |
| 88 | Ra | Radium | 2 |
| 89 | Ac | Actinium | 3 |
| 90 | Th | Thorium | 4, 3, 2 |
| 91 | Pa | Protactinium | 5, 4, 3 |
| 92 | U | Uranium | 6, 5, 4, 3, 2 |
| 93 | Np | Neptunium | 7, 6, 5, 4, 3, 2 |
| 94 | Pu | Plutonium | 7, 6, 5, 4, 3, 2 |
| 95 | Am | Americium | 7, 6, 5, 4, 3, 2 |
| 96 | Cm | Curium | 6, 5, 4, 3, 2 |
| 97 | Bk | Berkelium | 4, 3, 2 |
| 98 | Cf | Californium | 5, 4, 3, 2 |
| 99 | Es | Einsteinium | 4, 3, 2 |
| 100 | Fm | Fermium | 4, 3, 2 |
| 101 | Md | Mendelevium | 3, 2, 1 |
| 102 | No | Nobelium | 3, 2 |
| 103 | Lr | Lawrencium | 3, 2 |
| 104 | Rf | Rutherfordium | 4, 3 |
| 105 | Db | Dubnium | 5, 4 |
| 106 | Sg | Seaborgium | 6, 5, 4 |
| 107 | Bh | Bohrium | 7, 6, 5, 4, 3 |
| 108 | Hs | Hassium | 8, 7, 4, 3, 2 |
| 109 | Mt | Meitnerium | 6, 5, 4, 3, 2, 1 |
| 110 | Ds | Darmstadtium | 6, 5, 4, 3, 2, 1 |
| 111 | Rg | Roentgenium | -1, +3 |
| 112 | Cn | Copernicium | +1, +2 |
| 113 | Nh | Nihonium | +1, +3 |
| 114 | Fl | Flerovium | 0, +1, +2, +4, +6 |
| 115 | Mc | Moscovium | +1, +3 |
| 116 | Lv | Livermorium | -2, +2, +4 |
| 117 | Ts | Tennessine | -1, +1, +3 |
| 118 | Og | Oganesson | -1. 0, +1, +2, +4, +6 |
References
- Brown, I. David (2016). Inorganic Chemistry: The Bond Valence Model (2nd ed.). International Union of Crystallography. Oxford: Oxford Science Publications.
- Karen, P.; McArdle, P.; Takats, J. (2016). “Comprehensive definition of oxidation state (IUPAC Recommendations 2016)”. Pure Appl. Chem. 88 (8): 831–839. doi:10.1515/pac-2015-1204
- Lange, Norbert A. (1952). Lange’s Handbook of Chemistry (8th ed.). Handbook Publishers.
- O’Dwyer, M.F.; Kent, J.E.; Brown, R. D. (1978). Valency. New York: Springer-Verlag.
- Smart, Lesley E.; Moore, Elaine A. (2016). Solid State Chemistry – An Introduction (4th ed.). Boca Raton: CRC Press.