95
Americium
Atomic Number95
Atomic Mass243 u
CategoryActinide
State at Room TempSolid
Year Discovered1944
About Americium
Sits in nearly every home, invisibly: a speck of americium-241 in a smoke detector ionizes air, and smoke blocks the current and triggers the alarm. Named after the Americas, in tribute to europium across the table. Made in reactors from plutonium. Also used to start nuclear reactors, in oil well logging, and as a portable neutron source.
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