95 Am 243

Americium

actinide

Properties

Atomic number
95
Atomic mass
243 u
Category
actinide
Group
f-block
Period
7
Block
f-block
State (room temp)
Solid
Outer-shell electrons
2
Electronegativity
1.13 (Pauling)
Density
12 g/cm³
Melting point
1175.85 °C
Boiling point
2606.85 °C

Electron configuration

1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s² 5f⁷

Noble-gas shorthand: [Rn] 5f⁷ 7s²

Electrons per shell: 2, 8, 18, 32, 25, 8, 2 — that's 2 in the outermost shell.

See how electron configuration is built →

Am
Bohr model — outer-shell electrons in blue

About 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.

Position in the periodic table

Open the interactive periodic table →

Data compiled from Wikipedia, PubChem, and IUPAC. Source.