Cm
Curium
Element 96 · Actinide
Curium (Cm)
Curium is a hard, dense, radioactive metal that glows red-purple in the dark.
- Actinide
- Period 7
- f-block series
- f-block
- solid at room temperature
- ☢ Radioactive
Key properties
- Atomic mass
- [247]
- u
- Electron configuration
- [Rn] 5f7 6d1 7s2
- Melting point
- 1,344.9 °C
- 1,618 K
- Boiling point
- 3,126.9 °C
- 3,400 K
- Density
- 13.51 g/cm³
- Electronegativity
- 1.3
- Pauling
- Atomic radius
- 245 pm
- van der Waals
- 1st ionisation energy
- 6.02 eV
Compare with every element:Electronegativity chartAtomic radius chartIonisation energy chartDensity chart of the elementsMelting point chartElectron configuration chart
Did you know?
Notable facts about curium
- 01
It was first made at the Manhattan Project’s Metallurgical Laboratory in Chicago.
- 02
Curium-244 powered the alpha-particle X-ray spectrometers on Mars rovers.
- 03
Its name honours both Marie and Pierre Curie for their work on radioactivity.
Applications
What is curium used for?
- Alpha sources for planetary instruments
- Production of heavier elements
- Research
History
Discovery & name origin
Discovered by
Year
Where
United States
Name origin
From Marie and Pierre Curie.
Atomic structure
Atomic properties
Atomic structure
Atomic properties
- Atomic number
- 96
- Atomic mass
- [247] u
- Group
- Actinides (3)
- Period
- 7
- Block
- f-block
- Electron configuration
- [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
- Electronegativity (Pauling)
- 1.3
- Electron affinity
- —
- Atomic radius (van der Waals)
- 245 pm
- Stable isotopes
- None — all isotopes are radioactive
Oxidation states
Highlighted: common oxidation states (+3).
Physical
Physical properties & colour
Physical
Physical properties & colour
- State at 20 °C
- Solid
- Melting point
- 1,618 K · 1,344.9 °C · 2,452.7 °F
- Boiling point
- 3,400 K · 3,126.9 °C · 5,660.3 °F
- Density
- 13.51 g/cm³
- Molar heat capacity
- —
- Appearance
- Silvery metallic, glows purple in the dark
- CPK model colour
- Copied
The CPK colour is the convention used for this element’s atoms in molecular models.
FAQ
Curium questions
What is Cm on the periodic table?
Cm is the symbol for curium, element 96 on the periodic table. It sits in period 7, in the f-block, in the actinide category, and has an atomic mass of [247].
What is the atomic number of curium?
Curium has atomic number 96, so every curium atom has 96 protons in its nucleus. Its symbol is Cm and its atomic mass is [247].
Who discovered curium?
Curium was discovered by Glenn T. Seaborg, Ralph A. James and Albert Ghiorso in 1944 (United States). The name comes from from Marie and Pierre Curie.
What is curium used for?
Curium is used for: alpha sources for planetary instruments; production of heavier elements; research.
Is curium a metal?
Yes. Curium is a actinide, one of the metallic elements.
What is the electron configuration of curium?
The electron configuration of curium is [Rn] 5f7 6d1 7s2. Its 96 electrons are arranged in shells as 2, 8, 18, 32, 25, 9, 2.