Atomic radii of the elements (data page)

The atomic radius of a chemical element is the distance from the centre of the nucleus to the outermost shell of the electron. Since the boundary is not a well-defined physical entity, there are various non-equivalent definitions of atomic radius. Depending on the definition, the term may apply only to isolated atoms, or also to atoms in condensed matter, covalently bound in molecules, or in ionized and excited states; and its value may be obtained through experimental measurements, or computed from theoretical models. Under some definitions, the value of the radius may depend on the atom's state and context.[1]

Atomic radii vary in a predictable and explicable manner across the periodic table. For instance, the radii generally decrease rightward along each period (row) of the table, from the alkali metals to the noble gases; and increase down each group (column). The radius increases sharply between the noble gas at the end of each period and the alkali metal at the beginning of the next period. These trends of the atomic radii (and of various other chemical and physical properties of the elements) can be explained by the electron shell theory of the atom; they provided important evidence for the development and confirmation of quantum theory.

Atomic radii

Note: All measurements given are in picometers (pm). For more recent data on covalent radii see Covalent radius.

atomic numbersymbolname empirical Calculated van der Waals Covalent (single bond) Covalent (triple bond) Metallic
1Hhydrogen 25 53 120 38 no data
2Hehelium 120 31 140 32 no data
3Lilithium 145 167 182 134 no data 152
4Beberyllium 105 112 153 a 90 85 112
5Bboron 85 87 192 a 82 73
6Ccarbon 70 67 170 77 60
7Nnitrogen 65 56 155 75 54
8Ooxygen 60 48 152 73 53
9Ffluorine 50 42 147 71 53
10Neneon 160 38 154 69 no data
11Nasodium 180 190 227 154 no data 186
12Mgmagnesium 150 145 173 130 127 160
13Alaluminium 125 118 184 a 118 111 143
14Sisilicon 110 111 210 111 102
15Pphosphorus 100 98 180 106 94
16Ssulfur 100 88 180 102 95
17Clchlorine 100 79 175 99 93
18Arargon 71 71 188 97 96
19Kpotassium 220 243 275 196 no data 227
20Cacalcium 180 194 231 a 174 133 197
21Scscandium 160 184 211 a 144 114 162 b
22Tititanium 140 176 no data 136 108 147
23Vvanadium 135 171 no data 125 106 134 b
24Crchromium 140 166 no data 127 103 128 b
25Mnmanganese 140 161 no data 139 103 127 b
26Feiron 140 156 no data 125 102 126 b
27Cocobalt 135 152 no data 126 96 125 b
28Ninickel 135 149 163 121 101 124 b
29Cucopper 135 145 140 138 120 128 b
30Znzinc 135 142 139 131 no data 134 b
31Gagallium 130 136 187 126 121 135 c
32Gegermanium 125 125 211 a 122 114
33Asarsenic 115 114 185 119 106
34Seselenium 115 103 190 116 107
35Brbromine 115 94 185 114 110
36Krkrypton no data 88 202 110 108
37Rbrubidium 235 265 303 a 211 no data 248
38Srstrontium 200 219 249 a 192 139 215
39Yyttrium 180 212 no data 162 124 180 b
40Zrzirconium 155 206 no data 148 121 160
41Nbniobium 145 198 no data 137 116 146 b
42Momolybdenum 145 190 no data 145 113 139 b
43Tctechnetium 135 183 no data 156 110 136 b
44Ruruthenium 130 178 no data 126 103 134 b
45Rhrhodium 135 173 no data 135 106 134 b
46Pdpalladium 140 169 163 131 112 137 b
47Agsilver 160 165 172 153 137 144 b
48Cdcadmium 155 161 158 148 no data 151 b
49Inindium 155 156 193 144 146 167
50Sntin 145 145 217 141 132
51Sbantimony 145 133 206 a 138 127
52Tetellurium 140 123 206 135 121
53Iiodine 140 115 198 133 125
54Xexenon no data 108 216 130 122
55Cscaesium 260 298 343 a 225 no data 265
56Babarium 215 253 268 a 198 149 222
57Lalanthanum 195 195 no data 169 139 187 b
58Cecerium 185 158 no data no data 131 181.8 c
59Prpraseodymium 185 247 no data no data 128 182.4 c
60Ndneodymium 185 206 no data no data no data 181.4 c
61Pmpromethium 185 205 no data no data no data 183.4 c
62Smsamarium 185 238 no data no data no data 180.4 c
63Eueuropium 185 231 no data no data no data 180.4 c
64Gdgadolinium 180 233 no data no data 132 180.4 c
65Tbterbium 175 225 no data no data no data 177.3 c
66Dydysprosium 175 228 no data no data no data 178.1 c
67Hoholmium 175 226 no data no data no data 176.2 c
68Ererbium 175 226 no data no data no data 176.1 c
69Tmthulium 175 222 no data no data no data 175.9 c
70Ybytterbium 175 222 no data no data no data 176 c
71Lulutetium 175 217 no data 160 131 173.8 c
72Hfhafnium 155 208 no data 150 122 159
73Tatantalum 145 200 no data 138 119 146 b
74Wtungsten 135 193 no data 146 115 139 b
75Rerhenium 135 188 no data 159 110 137 b
76Ososmium 130 185 no data 128 109 135 b
77Iriridium 135 180 no data 137 107 135.5 b
78Ptplatinum 135 177 175 128 110 138.5 b
79Augold 135 174 166 144 123 144 b
80Hgmercury 150 171 155 149 no data 151 b
81Tlthallium 190 156 196 148 150 170
82Pblead 180 154 202 147 137
83Bibismuth 160 143 207 a 146 135
84Popolonium 190 135 197 a no data 129
85Atastatine no data 127 202 a no data 138
86Rnradon no data 120 220 a 145 133
87Frfrancium no data no data 348 a no data no data no data
88Raradium 215 no data 283 a no data 159 no data
89Acactinium 195 no data no data no data 140
90Ththorium 180 no data no data no data 136 179 b
91Paprotactinium 180 no data no data no data 129 163 d
92Uuranium 175 no data 186 no data 118 156 e
93Npneptunium 175 no data no data no data 116 155 e
94Puplutonium 175 no data no data no data no data 159 e
95Amamericium 175 no data no data no data no data 173 b
96Cmcurium no data no data no data no data no data 174 b
97Bkberkelium no data no data no data no data no data 170 b
98Cfcalifornium no data no data no data no data no data 186+/- 2 b
99Eseinsteinium no data no data no data no data no data 186+/- 2 b
100Fmfermium no data no data no data no data no data no data
101Mdmendelevium no data no data no data no data no data no data
102Nonobelium no data no data no data no data no data no data
103Lrlawrencium no data no data no data no data no data no data
104Rfrutherfordium no data no data no data no data 131 no data
105Dbdubnium no data no data no data no data 126 no data
106Sgseaborgium no data no data no data no data 121 no data
107Bhbohrium no data no data no data no data 119 no data
108Hshassium no data no data no data no data 118 no data
109Mtmeitnerium no data no data no data no data 113 no data
110Dsdarmstadtium no data no data no data no data 112 no data
111Rgroentgenium no data no data no data no data 118 no data
112Cncopernicium no data no data no data no data 130 no data
113Nhnihonium no data no data no data no data no data no data
114Flflerovium no data no data no data no data no data no data
115Mcmoscovium no data no data no data no data no data no data
116Lvlivermorium no data no data no data no data no data no data
117Tstennessine no data no data no data no data no data no data
118Ogoganesson no data no data no data no data no data no data

See also

Notes

  • The radius of an atom is not a uniquely defined property and depends on the definition. Data derived from other sources with different assumptions cannot be compared.
  • † to an accuracy of about 5 pm
  • (a) These radii are taken from M. Mantina, A.C. Chamberlin, R. Valero, C.J. Cramer, and D.G. Truhlar, J. Phys. Chem. A 2009, 113, 5806.
  • (b) 12 coordinate
  • (c) gallium has an anomalous crystal structure
  • (d) 10 coordinate
  • (e) uranium, neptunium and plutonium have irregular structures

References

  1. Cotton, F. A.; Wilkinson, G. (1988). Advanced Inorganic Chemistry (5th ed.). Wiley. p. 1385. ISBN 978-0-471-84997-1.

Data is as quoted at http://www.webelements.com/ from these sources:

Atomic radius (empirical)

  • J.C. Slater (1964). "Atomic Radii in Crystals". J. Chem. Phys. 41: 3199. Bibcode:1964JChPh..41.3199S. doi:10.1063/1.1725697.

Atomic radius (calculated)

  • E. Clementi; D.L.Raimondi; W.P. Reinhardt (1967). "Atomic Screening Constants from SCF Functions. II. Atoms with 37 to 86 Electrons". J. Chem. Phys. 47: 1300. Bibcode:1967JChPh..47.1300C. doi:10.1063/1.1712084.

Van der Waals radius

  • A. Bondi (1964). "van der Waals Volumes and Radii". J. Phys. Chem. 68: 441. doi:10.1021/j100785a001.
  • M. Mantina; A.C. Chamberlin; R. Valero; C.J. Cramer; D.G. Truhlar (2009). "Consistent van der Waals Radii for the Whole Main Group". J. Phys. Chem. A. 113 (19): 5806–12. Bibcode:2009JPCA..113.5806M. doi:10.1021/jp8111556. PMID 19382751.

Covalent radii (single bond)

More recent data can be found in Covalent radius. The above values are based on

  • R.T. Sanderson (1962). Chemical Periodicity. New York, USA: Reinhold.
  • L.E. Sutton, ed. (1965). "Supplement 1956–1959, Special publication No. 18". Table of interatomic distances and configuration in molecules and ions. London, UK: Chemical Society.
  • J.E. Huheey; E.A. Keiter & R.L. Keiter (1993). Inorganic Chemistry : Principles of Structure and Reactivity (4th ed.). New York, USA: HarperCollins. ISBN 0-06-042995-X.
  • W.W. Porterfield (1984). Inorganic chemistry, a unified approach. Reading Massachusetts, USA: Addison Wesley Publishing Co. ISBN 0-201-05660-7.
  • A.M. James & M.P. Lord (1992). Macmillan's Chemical and Physical Data. MacMillan. ISBN 0-333-51167-0.

Triple-bond covalent radii

  • S. Riedel; P.Pyykkö, M. Patzschke; Patzschke, M (2005). "Triple-Bond Covalent Radii". Chem. Eur. J. 11 (12): 3511–3520. doi:10.1002/chem.200401299. PMID 15832398. Mean-square deviation 3pm.
  • Triple-Bond Covalent Radii Table online

Metallic radius

Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 0-08-037941-9.

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