Th
Thorium
Z 90 232.038 g/molActinide Radioactive
Nucleus
90 Protons
142 Neutrons
90 Electrons (4 Valence)
Shell distribution: K2 • L8 • M18 • N32 • O18 • P10 • Q2
Electron Configuration
Energy
7p
6d
5f
7s
6p
5d
4f
6s
5p
4d
5s
4p
3d
4s
3p
3s
2p
2s
1s
[Rn]6d27s2
Oxidation States
CommonRare
0
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Radii
Empirical
180 pm1.8 Å
Calculated
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Covalent
206±6 pm2.06±0.06 Å
Van der Waals
237 pm2.37 Å
IonicTh4+
94 pm0.94 Å
Crystal Structure
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Face-centered cubicStandard state
Pearson symbol
cF4
Space group
Fm3m No. 225
Density
11.7 g/cm³