9 Be beryllium 4 24 Mg magnesium 12 40 Ca calcium 20 88 Sr strontium 38 137 Ba barium 56 [226] Ra radium 88 7 Li lithium 3 23 Na sodium 11 39 K potassium 19 85 Rb rubidium 37 133 Cs caesium 55 [223] Fr francium 87 89 actinium 57 [227] Ac* lanthanum 39 139 La* yttrium 21 89 Y scandium 45 Sc 104 rutherfordium 72 [267] Rf hafnium 40 178 Hf zirconium 22 91 Zr titanium 48 Ti 105 55 Mn 25 [97] Tc 74 [269] Sg tungsten 42 184 W 106 107 bohrium 75 [270] Bh rhenium 43 186 Re molybdenum technetium 24 96 Mo chromium manganese 52 Cr dubnium seaborgium 73 [270] Db tantalum 41 181 Ta niobium 23 93 Nb vanadium 51 V atomic (proton) number name relative atomic mass atomic symbol Key 108 hassium 76 [270] Hs osmium 44 190 Os ruthenium 26 101 Ru iron 56 Fe 59 Co 59 Ni 63.5 Cu 65 Zn 78 [281] Ds platinum 46 195 Pt palladium 28 106 Pd nickel 79 [281] Rg gold 47 197 Au silver 29 108 Ag copper 80 [285] Cn mercury 48 201 Hg cadmium 30 112 Cd zinc 109 110 111 112 meitnerium darmstadtium roentgenium copernicium 77 [278] Mt iridium 45 192 Ir rhodium 27 103 Rh cobalt 113 nihonium 81 [286] Nh thallium 49 204 Tl indium 31 115 In gallium 13 70 Ga aluminium 5 27 Al boron 11 B 114 flerovium 82 [289] FI lead 50 207 Pb tin 32 119 Sn germanium 14 73 Ge silicon 6 28 Si carbon 12 C Insert for GCSE Chemistry (8462), Combined Science: Trilogy (8464), and Combined Science: Synergy (8465) papers v2 Relative atomic masses for Cu and Cl have not been rounded to. the nearest whole number. 84 [293] Lv polonium 52 [209] Po tellurium 34 128 Te selenium 16 79 Se sulfur 8 32 S oxygen 16 O 85 [293] Ts astatine 53 [210] At iodine 35 127 I bromine 17 80 Br chlorine 9 35.5 Cl fluorine 19 F 115 116 117 moscovium livermorium tennessine 83 [289] Mc bismuth 51 209 Bi antimony 33 122 Sb arsenic 15 75 As phosphorus 7 31 P nitrogen 14 N 118 oganesson 86 [294] Og radon 54 [222] Rn xenon 36 131 Xe krypton 18 84 Kr argon 10 40 Ar neon 2 20 Ne 0 helium 7 1 6 hydrogen 5 4 He 4 1 H 3 * The Lanthanides (atomic numbers 58 – 71) and the Actinides (atomic numbers 90 – 103) have been omitted. 2 1 The Periodic Table of Elements