Valence electrons:
- The valence electrons are the electrons in the outermost orbit of atoms in a main group element (i.e., s-block and p-block elements).
- For most of the transition and inner transition elements, the valence electrons are primarily found in the shells outside of the noble gas core.
| Atomic Number | Element | Valence Electrons | Valence Electrons |
|---|---|---|---|
| 1 | Hydrogen (H) | 1 | 1s1 |
| 2 | Helium (He) | 2 | 1s2 |
| 3 | Lithium (Li) | 1 | 2s1 |
| 4 | Beryllium (Be) | 2 | 2s2 |
| 5 | Boron (B) | 3 | 2s2 2p1 |
| 6 | Carbon (C) | 4 | 2s2 2p2 |
| 7 | Nitrogen (N) | 5 | 2s2 2p3 |
| 8 | Oxygen (O) | 6 | 2s2 2p4 |
| 9 | Fluorine (F) | 7 | 2s2 2p5 |
| 10 | Neon (Ne) | 8 | 2s2 2p6 |
| 11 | Sodium (Na) | 1 | 3s1 |
| 12 | Magnesium (Mg) | 2 | 3s2 |
| 13 | Aluminum (Al) | 3 | 3s2 3p1 |
| 14 | Silicon (Si) | 4 | 3s2 3p2 |
| 15 | Phosphorus (P) | 5 | 3s2 3p3 |
| 16 | Sulfur (S) | 6 | 3s2 3p4 |
| 17 | Chlorine (Cl) | 7 | 3s2 3p5 |
| 18 | Argon (Ar) | 8 | 3s2 3p6 |
| 19 | Potassium (K) | 1 | 4s1 |
| 20 | Calcium (Ca) | 2 | 4s2 |
| 21 | Scandium (Sc) | 3 | 3d1 4s2 |
| 22 | Titanium (Ti) | 4 | 3d2 4s2 |
| 23 | Vanadium (V) | 5 | 3d3 4s2 |
| 24 | Chromium (Cr) | 6 | 3d5 4s1 |
| 25 | Manganese (Mn) | 7 | 3d5 4s2 |
| 26 | Iron (Fe) | 8 | 3d6 4s2 |
| 27 | Cobalt (Co) | 9 | 3d7 4s2 |
| 28 | Nickel (Ni) | 10 | 3d8 4s2 |
| 29 | Copper (Cu) | 11 | 3d10 4s1 |
| 30 | Zinc (Zn) | 12 | 3d10 4s2 |
| 31 | Gallium (Ga) | 3 | 4s2 4p1 |
| 32 | Germanium (Ge) | 4 | 4s2 4p2 |
| 33 | Arsenic (As) | 5 | 4s2 4p3 |
| 34 | Selenium (Se) | 6 | 4s2 4p4 |
| 35 | Bromine (Br) | 7 | 4s2 4p5 |
| 36 | Krypton (Kr) | 8 | 4s2 4p6 |
| 37 | Rubidium (Rb) | 1 | 5s1 |
| 38 | Strontium (Sr) | 2 | 5s2 |
| 39 | Yttrium (Y) | 3 | 4d1 5s2 |
| 40 | Zirconium (Zr) | 4 | 4d2 5s2 |
| 41 | Niobium (Nb) | 5 | 4d4 5s1 |
| 42 | Molybdenum (Mo) | 6 | 4d5 5s1 |
| 43 | Technetium (Tc) | 7 | 4d5 5s2 |
| 44 | Ruthenium (Ru) | 8 | 4d7 5s1 |
| 45 | Rhodium (Rh) | 9 | 4d8 5s1 |
| 46 | Palladium (Pd) | 10 | 4d10 |
| 47 | Silver (Ag) | 11 | 4d10 5s1 |
| 48 | Cadmium (Cd) | 12 | 4d10 5s2 |
| 49 | Indium (In) | 3 | 5s2 5p1 |
| 50 | Tin (Sn) | 4 | 5s2 5p2 |
| 51 | Antimony (Sb) | 5 | 5s2 5p3 |
| 52 | Tellurium (Te) | 6 | 5s2 5p4 |
| 53 | Iodine (I) | 7 | 5s2 5p5 |
| 54 | Xenon (Xe) | 8 | 5s2 5p6 |
| 55 | Cesium (Cs) | 1 | 6s1 |
| 56 | Barium (Ba) | 2 | 6s2 |
| 57 | Lanthanum (La) | 3 | 5d1 6s2 |
| 58 | Cerium (Ce) | 4 | 4f1 5d1 6s2 |
| 59 | Praseodymium (Pr) | 5 | 4f3 6s2 |
| 60 | Neodymium (Nd) | 6 | 4f4 6s2 |
| 61 | Promethium (Pm) | 7 | 4f5 6s2 |
| 62 | Samarium (Sm) | 8 | 4f6 6s2 |
| 63 | Europium (Eu) | 9 | 4f7 6s2 |
| 64 | Gadolinium (Gd) | 10 | 4f7 5d1 6s2 |
| 65 | Terbium (Tb) | 11 | 4f9 6s2 |
| 66 | Dysprosium (Dy) | 12 | 4f10 6s2 |
| 67 | Holmium (Ho) | 13 | 4f11 6s2 |
| 68 | Erbium (Er) | 14 | 4f12 6s2 |
| 69 | Thulium (Tm) | 15 | 4f13 6s2 |
| 70 | Ytterbium (Yb) | 16 | 4f14 6s2 |
| 71 | Lutetium (Lu) | 3 | 5d1 6s2 |
| 72 | Hafnium (Hf) | 4 | 5d2 6s2 |
| 73 | Tantalum (Ta) | 5 | 5d3 6s2 |
| 74 | Tungsten (W) | 6 | 5d4 6s2 |
| 75 | Rhenium (Re) | 7 | 5d5 6s2 |
| 76 | Osmium (Os) | 8 | 5d6 6s2 |
| 77 | Iridium (Ir) | 9 | 5d7 6s2 |
| 78 | Platinum (Pt) | 10 | 5d9 6s1 |
| 79 | Gold (Au) | 11 | 5d10 6s1 |
| 80 | Mercury (Hg) | 12 | 5d10 6s2 |
| 81 | Thallium (Tl) | 3 | 6s2 6p1 |
| 82 | Lead (Pb) | 4 | 6s2 6p2 |
| 83 | Bismuth (Bi) | 5 | 6s2 6p3 |
| 84 | Polonium (Po) | 6 | 6s2 6p4 |
| 85 | Astatine (At) | 7 | 6s2 6p5 |
| 86 | Radon (Rn) | 8 | 6s2 6p6 |
| 87 | Francium (Fr) | 1 | 7s1 |
| 88 | Radium (Ra) | 2 | 7s2 |
| 89 | Actinium (Ac) | 3 | 6d1 7s2 |
| 90 | Thorium (Th) | 4 | 6d2 7s2 |
| 91 | Protactinium (Pa) | 5 | 5f2 6d1 7s2 |
| 92 | Uranium (U) | 6 | 5f3 6d1 7s2 |
| 93 | Neptunium (Np) | 7 | 5f4 6d1 7s2 |
| 94 | Plutonium (Pu) | 8 | 5f6 7s2 |
| 95 | Americium (Am) | 9 | 5f7 7s2 |
| 96 | Curium (Cm) | 10 | 5f7 6d1 7s2 |
| 97 | Berkelium (Bk) | 11 | 5f9 7s2 |
| 98 | Californium (Cf) | 12 | 5f10 7s2 |
| 99 | Einsteinium (Es) | 13 | 5f11 7s2 |
| 100 | Fermium (Fm) | 14 | 5f12 7s2 |
| 101 | Mendelevium (Md) | 15 | 5f13 7s2 |
| 102 | Nobelium (No) | 16 | 5f14 7s2 |
| 103 | Lawrencium (Lr) | 3 | 7s2 7p1 |
| 104 | Rutherfordium (Rf) | 4 | 6d2 7s2 |
| 105 | Dubnium (Db) | 5 | 6d3 7s2 |
| 106 | Seaborgium (Sg) | 6 | 6d4 7s2 |
| 107 | Bohrium (Bh) | 7 | 6d5 7s2 |
| 108 | Hassium (Hs) | 8 | 6d6 7s2 |
| 109 | Meitnerium (Mt) | 9 | 6d7 7s2 |
| 110 | Darmstadtium (Ds) | 10 | 6d9 7s1 |
| 111 | Roentgenium (Rg) | 11 | 6d10 7s1 |
| 112 | Copernicium (Cn) | 12 | 6d10 7s2 |
| 113 | Nihonium (Nh) | 3 | 7s2 7p1 |
| 114 | Flerovium (Fl) | 4 | 7s2 7p2 |
| 115 | Moscovium (Mc) | 5 | 7s2 7p3 |
| 116 | Livermorium (Lv) | 6 | 7s2 7p4 |
| 117 | Tennessine (Ts) | 7 | 7s2 7p5 |
| 118 | Oganesson (Og) | 8 | 7s2 7p6 |