Main Page | See live article | Alphabetical index No. Element K L M N O P Q 1 Hydrogen 1 2 Helium 2 3 Lithium 2 1 4 Beryllium 2 2 5 Boron 2 3 6 Carbon 2 4 7 Nitrogen 2 5 8 Oxygen 2 6 9 Fluorine 2 7 10 Neon 2 8 11 Sodium 2 8 1 12 Magnesium 2 8 2 13 Aluminium 2 8 3 14 Silicon 2 8 4 15 Phosphorus 2 8 5 16 Sulfur 2 8 6 17 Chlorine 2 8 7 18 Argon 2 8 8 19 Potassium 2 8 8 1 20 Calcium 2 8 8 2 21 Scandium 2 8 9 2 22 Titanium 2 8 10 2 23 Vanadium 2 8 11 2 24 Chromium 2 8 13 1 25 Manganese 2 8 13 2 26 Iron 2 8 14 2 27 Cobalt 2 8 15 2 28 Nickel 2 8 16 2 29 Copper 2 8 18 1 30 Zinc 2 8 18 2 31 Gallium 2 8 18 3 32 Germanium 2 8 18 4 33 Arsenic 2 8 18 5 34 Selenium 2 8 18 6 35 Bromine 2 8 18 7 36 Krypton 2 8 18 8 37 Rubidium 2 8 18 8 1 38 Strontium 2 8 18 8 2 39 Yttrium 2 8 18 9 2 40 Zirconium 2 8 18 10 2 41 Niobium 2 8 18 12 1 42 Molybdenum 2 8 18 13 1 43 Technetium 2 8 18 14 1 44 Ruthenium 2 8 18 15 1 45 Rhodium 2 8 18 16 1 46 Palladium 2 8 18 18 0 47 Silver 2 8 18 18 1 48 Cadmium 2 8 18 18 2 49 Indium 2 8 18 18 3 50 Tin 2 8 18 18 4 51 Antimony 2 8 18 18 5 52 Tellurium 2 8 18 18 6 53 Iodine 2 8 18 18 7 54 Xenon 2 8 18 18 8 55 Caesium 2 8 18 18 8 1 56 Barium 2 8 18 18 8 2 57 Lanthanum 2 8 18 18 9 2 58 Cerium 2 8 18 19 9 2 59 Praseodymium 2 8 18 21 8 2 60 Neodymium 2 8 18 22 8 2 61 Promethium 2 8 18 23 8 2 62 Samarium 2 8 18 24 8 2 63 Europium 2 8 18 25 8 2 64 Gadolinium 2 8 18 25 9 2 65 Terbium 2 8 18 27 8 2 66 Dysprosium 2 8 18 28 8 2 67 Holmium 2 8 18 29 8 2 68 Erbium 2 8 18 30 8 2 69 Thulium 2 8 18 31 8 2 70 Ytterbium 2 8 18 32 8 2 71 Lutetium 2 8 18 32 9 2 72 Hafnium 2 8 18 32 10 2 73 Tantalum 2 8 18 32 11 2 74 Tungsten 2 8 18 32 12 2 75 Rhenium 2 8 18 32 13 2 76 Osmium 2 8 18 32 14 2 77 Iridium 2 8 18 32 15 2 78 Platinum 2 8 18 32 17 1 79 Gold 2 8 18 32 18 1 80 Mercury 2 8 18 32 18 2 81 Thallium 2 8 18 32 18 3 82 Lead 2 8 18 32 18 4 83 Bismuth 2 8 18 32 18 5 84 Polonium 2 8 18 32 18 6 85 Astatine 2 8 18 32 18 7 86 Radon 2 8 18 32 18 8 87 Francium 2 8 18 32 18 8 1 88 Radium 2 8 18 32 18 8 2 89 Actinium 2 8 18 32 18 9 2 90 Thorium 2 8 18 32 18 10 2 91 Protactinium 2 8 18 32 20 9 2 92 Uranium 2 8 18 32 21 9 2 93 Neptunium 2 8 18 32 22 9 2 94 Plutonium 2 8 18 32 24 8 2 95 Americium 2 8 18 32 25 8 2 96 Curium 2 8 18 32 25 9 2 97 Berkelium 2 8 18 32 27 8 2 98 Californium 2 8 18 32 28 8 2 99 Einsteinium 2 8 18 32 29 8 2 100 Fermium 2 8 18 32 30 8 2 101 Mendelevium 2 8 18 32 31 8 2 102 Nobelium 2 8 18 32 32 8 2 103 Lawrencium 2 8 18 32 32 9 2 104 Rutherfordium 2 8 18 32 32 10 2 105 Dubnium 2 8 18 32 32 11 2 106 Seaborgium 2 8 18 32 32 12 2 107 Bohrium 2 8 18 32 32 13 2 108 Hassium 2 8 18 32 32 14 2 109 Meitnerium 2 8 18 32 32 15 2 110 Darmstadtium 2 8 18 32 32 16 2 111 Unununium 2 8 18 32 32 17 2 112 Ununbium 2 8 18 32 32 18 2 113 Ununtrium 2 8 18 32 32 18 3 114 Ununquadium 2 8 18 32 32 18 4 115 Ununpentium 2 8 18 32 32 18 5 116 Ununhexium 2 8 18 32 32 18 6 117 Ununseptium 2 8 18 32 32 18 7 118 Ununoctium 2 8 18 32 32 18 8 Niels Bohr's electron orbital shell model utilizes the letters K through Q to label the atomic orbitals in the various elements. The maximum occupancy of a shell is represented by where n is the index of the shell. The number of electrons in a neutral atom increases with the atomic number. The electrons in the outermost shell, or valence electrons, tend to be responsible for an element's chemical behavior. Elements that contain the same number of valence electrons can be grouped together and display similar chemical properties. Each horizontal row is described as a period. The numbers in each column, or shell, refer to the number of electrons. For example, Helium has two electrons, both of which occupy the K shell. See also Periodic table Periodic table group Periodic table period Chemical series Periodic table block Isotope table (complete) Isotope table (divided) Discovery of the chemical elements Elements song IUPAC's systematic element names. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.