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Atomic radius


What is meant by the atomic radius? Definition and explanation ...

As atomic radius In general, the distance between the atomic nucleus and the electron cloud can be defined. All values ​​for the atomic radius can therefore at best be approximate values, because the distance between the nucleus and the outermost electron in the electron shell is practically barely measurable. Atoms are not unique 'entities', with a clearly defined beginning and end.
The information on the atomic radii (in pikometers with the factor 10-12) of the respective chemical elements vary z.T. very clearly. The table below does not, therefore, claim to be universally valid.
The final distance of the atomic radius is, however, also strongly dependent on the definition. Therefore one distinguishes between the following radii in chemistry:
ionic radius: half the distance between two atoms in an ionic bond.
Bohr radius: Distance between proton and electron in a hydrogen atom in its ground state (state with the lowest possible energy).
Covalent radius: half the distance between two covalently bonded atoms of the same element.
Metallic radius: half the distance between two atoms in a metallic bond.
Van der Waals radius: Distance between atomic nucleus and atomic shell in an imaginary imaginary sphere.

List of atomic radii:

ordinalChem. ElementAtomic radius (in pm)
1hydrogen25
2helium31
3lithium145
4beryllium105
5boron85
6carbon70
7nitrogen65
8oxygen60
9fluorine50
10neon38
11sodium180
12magnesium150
13aluminum125
14silicon110
15phosphorus100
16sulfur100
17chlorine100
18argon71
19potassium220
20calcium180
21scandium160
22titanium140
23vanadium135
24chrome140
25manganese140
26iron140
27cobalt135
28nickel135
29copper135
30zinc135
31gallium130
32germanium125
33arsenic115
34selenium115
35bromine115
36krypton88
37rubidium235
38strontium200
39yttrium180
40zirconium155
41niobium145
42molybdenum145
43technetium135
44ruthenium130
45rhodium135
46palladium140
47silver160
48cadmium155
49indium155
50tin145
51antimony145
52tellurium140
53iodine140
54xenon108
55cesium265
56barium215
57lanthanum195
58cerium185
59praseodymium185
60neodymium185
61promethium185
62samarium185
63europium185
64gadolinium188
65terbium175
66dysprosium175
67holmium175
68erbium175
69thulium175
70ytterbium175
71lutetium175
72hafnium155
73tantalum145
74tungsten135
75rhenium135
76osmium130
77iridium135
78platinum135
79gold135
80mercury150
81thallium190
82lead180
83bismuth160
84polonium190
85astatine150
86radon130
87francium250
88radium215
89actinium195
90thorium180
91protactinium180
92uranium138
93neptunium155
94plutonium151
95americium184
96Curium174
97Berkelium170
98californium186
99Einsteinium203
100fermiumn / A.
101mendeleviumn / A.
102nobeliumn / A.
103lawrenciumn / A.
104rutherfordium150
105Dubnium139
106seaborgium132
107Bohrium128
108Hassium126
109Meitnerium122
110darmstadtium118
111Roentgenium114
112Copernicium110
113Ununtrium170
114Flerovium160
115Ununpentium200
116Livermoriumn / A.
117Ununseptiumn / A.
118Ununoctium152