Am
243.000Americium
Amerikyum
Americium is a synthetic radioactive actinide with atomic number 95. It is best known for americium-241 ionization smoke detectors, alpha emission, low-energy gamma radiation and heavy-actinide research.
95
243 g/mol
[Rn] 5f⁷ 7s²
2 | 8 | 18 | 32 | 25 | 8 | 2
1.3
13.67 g/cm³
1175.8 °C
2606.8 °C
Glenn T. Seaborg
Americium was synthesized in 1944 by Glenn Seaborg, Ralph James, Leon Morgan and Albert Ghiorso during the Manhattan Project. It was named after the Americas, by analogy with europium.
Americium-241
Half-life: About 432.2 years. Alpha emitter with weak gamma emission, widely used in ionization smoke detectors.Americium-243
Half-life: About 7,370 years. Long-lived americium isotope used in heavy actinide research.AmO₂
Americium DioxideCommon americium source material and research compound.AmCl₃
Americium(III) ChlorideResearch starting material for americium chemistry.- Americium-241 in ionization-type smoke detectors
- Industrial thickness, density and level gauges
- Neutron sources when mixed with beryllium
- Heavy actinide production and radiochemistry research
Americium has no biological role. Am-241 emits alpha particles and weak gamma radiation, so sealed sources are handled differently from internal contamination risks.
- A typical ionization smoke detector contains only a tiny sealed Am-241 source.
- Am-241 forms as plutonium-241 decays by beta emission.
- Americium’s 5f⁷ configuration is often compared with europium’s half-filled 4f shell.
- Americium has atomic number 95 and symbol Am.
- Its electron configuration is [Rn] 5f⁷ 7s².
- The +3 oxidation state is especially common.
- Remember Am-241 for ionization smoke detectors.
What is the atomic number of americium?
The atomic number of americium is 95.
What is the electron configuration of americium?
Americium has the electron configuration [Rn] 5f⁷ 7s².
What is americium used for?
Americium is used in ionization smoke detectors, industrial gauges, neutron sources and actinide research.
Why is americium used in smoke detectors?
Am-241 ionizes air between electrodes; smoke disrupts the ion current and triggers the alarm.
What is the half-life of americium-241?
Americium-241 has a half-life of about 432.2 years.