Ca
Calcium
Z 20 40.078 g/molAlkaline Earth Metal
Nucleus
20 Protons
20 Neutrons
20 Electrons (2 Valence)
Shell distribution: K2 • L8 • M8 • N2 • O0 • P0 • Q0
Electron Configuration
Energy
7p
6d
5f
7s
6p
5d
4f
6s
5p
4d
5s
4p
3d
4s
3p
3s
2p
2s
1s
[Ar]4s2
Radii
Empirical
180 pm1.8 Å
Calculated
194 pm1.94 Å
Covalent
176±10 pm1.76±0.1 Å
van Der Waals
231 pm2.31 Å
Oxidation States
CommonRare
0
+1
+2
Crystal Structure
Use the arrow keys to rotate, hold Shift with the left and right arrows to roll, and press Home to reset the view.
Face-centered Cubic