Am
Americium
Element 95 · 243.06138 u
Americium is found in nearly every household ionization smoke detector.
Physical Properties
| Atomic Mass | 243.06138 u |
| Density | 13.69 g/cm³ |
| Melting Point | 1449.0 K |
| Boiling Point | 2880.0 K |
| Appearance | Silvery-white metallic |
| State at Room Temp | Solid |
Chemical Properties
| Electronegativity | 1.3 (Pauling) |
| 1st Ionization Energy | 578.0 kJ/mol |
| Electron Affinity | 9.93 kJ/mol |
| Oxidation States | +2, +3, +4, +5, +6, +7 |
Atomic Properties
| Electron Configuration | [Rn] 5f7 7s2 |
| Atomic Radius | 173.0 pm |
| Van der Waals Radius | 244.0 pm |
Discovery
| Discovered By | Glenn T. Seaborg, Ralph A. James, Leon O. Morgan, Albert Ghiorso |
| Discovery Year | 1944 |
| Location | Chicago, Illinois, USA |
| Named After | Named after the Americas |
About Americium
Americium is the most commonly encountered synthetic element, present in ionization smoke detectors. Seaborg announced its discovery on a children's radio show.
Uses & Applications
Household smoke detectors (Am-241), neutron sources, and space probe power sources.
Fun Fact
Americium is in nearly every home in smoke detectors. Seaborg famously announced its discovery on a children's radio quiz show.
Isotopes
| Mass Number | Abundance | Half-Life | Stable |
| 241 | - | 432.2 years | No |
| 243 | - | 7,370 years | No |
Electron Configuration
[Rn] 5f7 7s2