Am
Americium
Atomic number: 95Mass: 243 uCategory: Actinide
About Americium
Americium is a radioactive transuranic chemical element. A common household use of americium is in ionisation-type smoke detectors, where a tiny amount of americium-241 is used to detect smoke.
Properties
Period
7
Group
N/A
Block
F
Category
Actinide
Electronegativity
1.30 (Pauling)
Ionization Energy
578 kJ/mol
Melting Point
1449 K (1176°C)
Boiling Point
2284 K (2011°C)
Density
13.67 g/cm³
Oxidation States
+3, +4, +5, +6
Electron Configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 6s² 6p⁶ 5f⁷ 7s²
[Rn] 5f⁷ 7s²
Shell 1:2e⁻
Shell 2:8e⁻
Shell 3:18e⁻
Shell 4:32e⁻
Shell 5:25e⁻
Shell 6:8e⁻
Shell 7:2e⁻
Real-World Uses
Smoke detectors (Am-241)
Neutron sources
Cancer radiotherapy
Thickness gauges
Research
Fun Fact
Your smoke detector almost certainly contains americium-241 — a radioactive element protecting you from fire every day in your home!