096Actinide · Group 3 · Period 7
Curium
Curium (Cm) is element 96, a actinide in the f-block — group 3, period 7. It is a solid at room temperature with 7 electron shells (2, 8, 18, 32, 25, 9, 2) and an atomic mass of 247 u.
- Atomic mass
- 247.0 u
- Phase · STP
- solid
- Melting
- 1613 K · 1340 °C
- Boiling
- 3383 K · 3110 °C
- Electronegativity
- 1.28
- Density
- 13.51 g/cm³
Photograph — European Union, The Actinide Group, Institute for Transuranium Elements (JRC-ITU), source: https://images-of-elements.com/curium.php
Identity
- Atomic number
- 96
- Standard atomic weight
- 247.0 u
- Category
- Actinide
- Group
- 3
- Period
- 7
- Block
- f-block
- Oxidation states
- +3
Physical properties
- Melting point
- 1613 K · 1340 °C
- Boiling point
- 3383 K · 3110 °C
- Density
- 13.51 g/cm³
- Molar heat capacity
- —
- Atomic radius
- 245 pm
- Electron affinity
- 27.17 kJ/mol
Atomic structure
96protons
151neutrons
96electrons
2valence e⁻
- Noble-gas notation
- [Rn] 5f7 6d1 7s2
- Full configuration
- 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f7 6d1
- Electrons per shell
- 2, 8, 18, 32, 25, 9, 2
Periodic trends
Where Curium ranks across all 118 elements.
Discovery
- Discovered
- 1944
- Discovered by
- Glenn T. Seaborg
- Named by
- —
- Appearance
- silvery metallic, glows purple in the dark