The values of Table 3 show the covalent radii from the two recent original determinations by Cordero et al.[1], and Pyykkö and Atsumi [2]. The differences between the two single-bond values are often explained by the different coordination numbers in the two data bases used. When the effective radii do not follow the natural order single > double > triple, it means that the changes in the radii of the ligands are even larger than those for the considered element. Atomic Number Element Covalent radii Atomic Number Element Single Bonds [1] Single Bonds [2] Double Bonds [2] Triple Bonds [2] 1 H 31 32 - - 2 He 28 46 - - 3 Li 128 133 124 - 4 Be 96 102 90 85 5 B 84 85 78 73 6 C 76 75 67 60 7 N 71 71 60 54 8 O 66 63 57 53 9 F 57 64 59 53 10 Ne 58 67 96 - 11 Na 166 155 160 - 12 Mg 141 139 132 127 13 Al 121 126 113 111 14 Si 111 116 107 102 15 P 107 111 102 94 16 S 105 103 94 95 17 Cl 102 99 95 93 18 Ar 106 96 107 96 19 K 203 196 193 - 20 Ca 176 171 147 133 21 Sc 170 148 116 114 22 Ti 160 136 117 108 23 v 153 134 112 106 24 Cr 139 122 111 103 25 Mn 150 119 105 103 26 Fe 142 116 109 102 27 Co 138 111 103 96 28 Ni 124 110 101 101 29 Cu 132 112 115 120 30 Zn 122 118 120 - 31 Ga 122 124 117 121 32 Ge 120 121 111 114 33 As 119 121 114 106 34 Se 120 116 107 107 35 Br 120 114 109 110 36 Kr 116 117 121 108 37 Rb 220 210 202 - 38 Sr 195 185 157 139 39 Y 190 163 130 124 40 Zr 175 154 127 121 41 Nb 164 147 125 116 42 Mo 154 138 121 113 43 Tc 147 128 120 110 44 Ru 146 125 114 103 45 Rh 142 125 110 106 46 Pd 139 120 117 112 47 Ag 145 128 139 137 48 Cd 144 136 144 - 49 In 142 142 136 146 50 Sn 139 140 130 132 51 Sb 139 140 133 127 52 Te 138 136 128 121 53 I 139 133 129 125 54 Xe 140 131 135 122 55 Cs 244 232 209 - 56 Ba 215 196 161 149 57 La 207 180 139 139 58 Ce 204 163 137 131 59 Pr 203 176 138 128 60 Nd 201 174 137 - 61 Pm 199 173 135 - 62 Sm 198 172 134 - 63 Eu 198 168 134 - 64 Gd 196 169 135 132 65 Tb 194 168 135 - 66 Dy 192 167 133 - 67 Ho 192 166 133 - 68 Er 189 165 133 - 69 Tm 190 164 131 - 70 Yb 187 170 129 - 71 Lu 187 162 131 131 72 Hf 175 152 128 122 73 Ta 170 146 126 119 74 W 162 137 120 115 75 Re 151 131 119 110 76 Os 144 129 116 109 77 Ir 141 122 115 107 78 Pt 136 123 112 110 79 Au 136 124 121 123 80 Hg 132 133 142 - 81 Tl 145 144 142 150 82 Pb 146 144 135 137 83 Bi 148 151 141 135 84 Po 140 145 135 129 85 At 150 147 138 138 86 Rn 150 142 145 133 87 Fr 260 223 218 - 88 Ra 221 201 173 159 89 Ac 215 186 153 140 90 Th 206 175 143 136 91 Pa 200 169 138 129 92 U 196 170 134 118 93 Np 190 171 136 116 94 Pu 187 172 135 - 95 Am 180 166 135 - 96 Cm 169 166 136 - 97 Bk - 168 139 - 98 Cf - 168 140 - 99 Es - 165 140 - 100 Fm - 167 - - 101 Md - 173 139 - 102 No - 176 159 - 103 Lr - 161 141 - 104 Rf - 157 140 131 105 Db - 149 136 126 106 Sg - 143 128 121 107 Bh - 141 128 119 108 Hs - 134 125 118 109 Mt - 129 125 113 110 Ds - 128 116 112 111 Rg - 121 116 118 112 Cn - 122 137 130 113 Uut - 136 - - 114 Uuq - 143 - - 115 Uup - 162 - - 116 Uuh - 175 - - 117 Uus - 165 - - 118 Uuo - 157 - - References Beatriz Cordero, Verónica Gómez, Ana E. Platero-Prats, Marc Revés, Jorge Echeverría, Eduard Cremades, Flavia Barragán and Santiago Alvarez (2008). "Covalent radii revisited". Dalton Trans. (21): 2832–2838 http://dx.doi.org/10.1039/b801115j Pekka Pyykkö, Michiko Atsumi (2009). "Molecular Double-Bond Covalent Radii for Elements Li–E112". Chemistry: A European Journal 15 (46): 12770–12779. dx.doi.org/10.1002/chem.200901472 Template:HideTOC