Radium (Ra)
Radium
Radium (Ra) is an alkaline earth metal in period 7, group 2. Its relative atomic mass is [226] and the molar mass of the atom is [226] g/mol.
Atomic number 88
Atomic mass [226] predicted
Molar mass [226] g/mol
Category Alkaline earth metal Solid
Properties of radium
| Atomic number | 88 |
|---|---|
| Symbol | Ra |
| Latin name | Radium |
| Relative atomic mass | [226] |
| Molar mass | [226] g/mol |
| Group, period, block | 2, 7, s |
| Category | Alkaline earth metal |
| State at 20 °C | Solid |
| Electron configuration | [Rn] 7s² |
| Electronegativity (Pauling) | 0.9 |
| Atomic radius | 215 pm |
Electron configuration of radium
Electrons per shell
K2L8M18N32O18P8Q2
Full notation
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 6s² 6p⁶ 7s²
Noble-gas notation
88 protons · 88 electrons[Rn] 7s²
Formula and compounds of radium
Simple substanceRaradiumMolar mass of Ra: [226] g/mol
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Frequently asked questions
The relative atomic mass of radium is [226], so the molar mass of the atom is [226] g/mol.
Full: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 6s² 6p⁶ 7s². Noble-gas notation: [Rn] 7s².