Americium
Americium is a radioactive transuranic chemical element with symbol Am and atomic number 95. This member of the actinide series is located in the periodic table under the lanthanide element europium, and thus by analogy was named after the Americas. Americium was first produced in 1944 by the group of Glenn T.Seaborg from Berkeley, California, at the metallurgical laboratory of University of Chicago.
A stylized shell model. Electrons are quantum objects, not particles following these literal paths. Sizes and motion are illustrative.
86 is the [Rn] core total across six shells.
At a glance
- Atomic number
- 95
- Atomic mass
- 243 u
- Phase
- Solid
- Density
- 12 g/cm³
- Melting point
- 1,449 K
- Boiling point
- 2,880 K
- First ionization energy
- 578 kJ/mol
- Electronegativity
- 1.13
- Electron affinity
- 9.93 kJ/mol
- Molar heat capacity
- 62.7 J/(mol·K)
- Period
- 7
- Appearance
- silvery white
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.