96CmCurium247[Rn] 5f⁷ 6d¹ 7s²
actinide

Curium

Curium is a transuranic radioactive chemical element with symbol Cm and atomic number 96. This element of the actinide series was named after Marie and Pierre Curie – both were known for their research on radioactivity. Curium was first intentionally produced and identified in July 1944 by the group of Glenn T. Seaborg at the University of California, Berkeley.

Electronic structure

A stylized shell model. Electrons are quantum objects, not particles following these literal paths. Sizes and motion are illustrative.

Electrons by shell
Electron configuration
5f7
6d1
7s2

86 is the [Rn] core total across six shells.

Properties

At a glance

Atomic number
96
Atomic mass
247 u
Phase
Solid
Density
13.51 g/cm³
Melting point
1,613 K
Boiling point
3,383 K
First ionization energy
581 kJ/mol
Electronegativity
1.28
Electron affinity
27.17 kJ/mol
Molar heat capacity
Unavailable
Period
7
Appearance
silvery metallic, glows purple in the dark

Conditions and isotopes affect measured properties. Some properties of short-lived elements are predicted. Electronegativity uses the Pauling scale.

Keep exploring

Explore the stories, imagery, and reference data in more depth. Properties with no value in the reference are marked unavailable.