88Solid
Ra 226 Atomic mass · uAlkaline earth metals
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).
Discovery 1898 (Pierre Curie)
K2L8M18N32O18P8Q2
Physical properties
Values for the element in its standard state.
- Density
- 5g/cm³
- Melting point
- 973K
- Boiling point
- 2,010K
- Atomic radius
- Not available
- Bonding type
- Metallic
- Molar heat
- Not available
Inside the atom
Electron arrangement and the energy behind its behavior.
Full electron configuration
1s, 2 electrons; 2s, 2 electrons; 2p, 6 electrons; 3s, 2 electrons; 3p, 6 electrons; 3d, 10 electrons; 4s, 2 electrons; 4p, 6 electrons; 4d, 10 electrons; 5s, 2 electrons; 5p, 6 electrons; 4f, 14 electrons; 5d, 10 electrons; 6s, 2 electrons; 6p, 6 electrons; 7s, 2 electrons;
[Rn] represents 86 core electrons. The full view shows them explicitly.
88 electrons Orbital order preserved from source
- Electronegativity
- 0.9Pauling scale
- First ionization energy
- 509kJ/mol
- Electron affinity
- Not available
- Van der Waals radius
- Not available
Ra RadiumAtomic number 88
509kJ/mol
Atomic numberGaps indicate unavailable data
About radium
- Appearance
- Silvery white metallic
- Discovery
- 1898 (Pierre Curie)
- Data source
- Read the reference
A missing value means it is unavailable in this reference dataset. Values can vary with measurement method and conditions.