Element 95
Americium
Actinides
Americium (Am) is in the f-block of the periodic table — group 3, period 7.
Americium is a radioactive transuranic chemical element with symbol Am and atomic number 95.
Key data
- Atomic number
- 95
- Atomic mass
- 243.000 u
- Group / Period
- 3 / 7
- Block
- f-block
- Phase at STP
- Solid
- Density
- 12 g/cm³
- Melting point
- 1175.8 °C
- Boiling point
- 2606.8 °C
- Electron configuration
- [Rn] 5f7 7s2
Periodic table block
Americium is in the f-block (group 3, period 7). Elements land in the f-block when their highest-energy electrons fill an f subshell — these are the lanthanides and actinides shown beneath the main table.
New to this? Periodic table blocks explained: s, p, d, and f
Common uses
- •Smoke detectors
- •Industrial gauging
- •Research only
Discovery
Year: 1944
Discovered by: Glenn T. Seaborg
Frequently asked questions
What is the atomic number of Americium?
Americium has atomic number 95. Its symbol is Am and its atomic mass is 243 u.
What category of element is Americium?
Americium is classified as actinides. It sits in group 3, period 7 of the periodic table.
What block of the periodic table is Americium in?
Americium is in the f-block (group 3, period 7). Its highest-energy electrons occupy the f subshell — you can see this in its electron configuration, [Rn] 5f7 7s2.
What is Americium used for?
Common uses of Americium include: Smoke detectors, Industrial gauging, Research only.
When was Americium discovered?
Americium was discovered in 1944 by Glenn T. Seaborg.
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