88 Ra 226
Radium
alkaline earth metal
Properties
- Atomic number
- 88
- Atomic mass
- 226 u
- Category
- alkaline earth metal
- Group
- 2
- Period
- 7
- Block
- s-block
- State (room temp)
- Solid
- Outer-shell electrons
- 2
- Electronegativity
- 0.9 (Pauling)
- Density
- 5.5 g/cm³
- Melting point
- 959.85 °C
- Boiling point
- 1736.85 °C
Electron configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s²
Noble-gas shorthand: [Rn] 7s²
Electrons per shell: 2, 8, 18, 32, 18, 8, 2 — that's 2 in the outermost shell.
About Radium
Radium is a chemical element with symbol Ra and atomic number 88. It is the sixth element in group 2 of the periodic table, also known as the alkaline earth metals. Pure radium is almost colorless, but it readily combines with nitrogen (rather than oxygen) on exposure to air, forming a black surface layer of radium nitride (Ra3N2).
- Discovered by Pierre Curie
- Appearance: silvery white metallic
Position in the periodic table
Data compiled from Wikipedia, PubChem, and IUPAC. Source.