Calcium (Ca)
Calcium
Calcium (Ca) is an alkaline earth metal in period 4, group 2. Its relative atomic mass is 40.078 and the molar mass of the atom is 40.078 g/mol.
Atomic number 20
Atomic mass 40.078
Molar mass 40.078 g/mol
Category Alkaline earth metal Solid
Properties of calcium
| Atomic number | 20 |
|---|---|
| Symbol | Ca |
| Latin name | Calcium |
| Relative atomic mass | 40.078 |
| Molar mass | 40.078 g/mol |
| Group, period, block | 2, 4, s |
| Category | Alkaline earth metal |
| State at 20 °C | Solid |
| Electron configuration | [Ar] 4s² |
| Electronegativity (Pauling) | 1 |
| Atomic radius | 180 pm |
Electron configuration of calcium
Electrons per shell
K2L8M8N2
Full notation
1s² 2s² 2p⁶ 3s² 3p⁶ 4s²
Noble-gas notation
20 protons · 20 electrons[Ar] 4s²
Formula and compounds of calcium
Simple substanceCacalciumMolar mass of Ca: 40.078 g/mol
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Frequently asked questions
The relative atomic mass of calcium is 40.078, so the molar mass of the atom is 40.078 g/mol.
Full: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s². Noble-gas notation: [Ar] 4s².