Periodic TableAll elementsCurium
No. 096
Cm
247 u
Element · Actinide

Curium

Curium (锔, symbol Cm) is chemical element number 96, an Actinide in period 7 of the periodic table, with a standard atomic weight of about 247. Hard, dense radioactive metal. Named in honor of Marie and Pierre Curie.

Period 7Group —[Rn] 5f⁷ 6d¹ 7s²

Properties

Atomic number96
SymbolCm
Atomic mass247 u
CategoryActinide
Period7
Group
Electron configuration[Rn] 5f⁷ 6d¹ 7s²
Electronegativity1.28
Covalent radius169 pm
Density13.51 g/cm³
Melting point1613 K
Boiling point3383 K
DiscoverySeaborg, James, Ghiorso, 1944

Overview

Hard, dense radioactive metal. Named in honor of Marie and Pierre Curie. Curium (symbol Cm) is chemical element number 96, sitting in period 7 of the periodic table and classed as an Actinide. As an actinide it is typically radioactive and closely tied to nuclear technology.

It has the configuration [Rn] 5f⁷ 6d¹ 7s² and an electronegativity near 1.28; its 2 outer-shell electrons drive its bonding. Under standard conditions it exists as a solid; it melts near 1613 K (1339.9 °C), boils near 3383 K (3109.9 °C), has a density around 13.51 g/cm³.

It is widely used in Research and Energy / Batteries. It is regarded as a high-hazard element, so handle it with appropriate care. It was first described by Seaborg, James, Ghiorso in 1944.

Electron shells

Cm96

Electrons per shell: 2 · 8 · 18 · 32 · 25 · 9 · 2

Main uses

Hazard

HighRadioactive

Compounds containing Curium

No compounds in this knowledge base contain Curium yet.

Data sources

Atomic mass uses IUPAC (CIAAW) standard atomic weights; the covalent radius is from Cordero et al. (2008). Verify on the RSC Periodic Table, PubChem and Wikipedia. Educational reference only.