The metallic element americium is not found in nature. Instead, it is produced inside nuclear reactors when uranium or plutonium atoms are bombarded with neutrons. Surprisingly, americium is the most commonly used radioactive element in the home. The radioactivity emitted by americium atoms causes the air inside smoke detectors to conduct electricity. When the smoke interrupts the electrical current, an alarm sounds.
Summary of properties (Am)
| Atomic weight | [243] |
| Discoverer (year) | Seaborg, Glenn T. (1944) |
| Natural form | metallic solid (hexagonal) |
| Electron configuration | [Rn] 5f 7 7s2 |
| Melting point (ºC) | 994 |
| Boiling point (ºC) | 2607 |
| Abundance in earth's crust (ppm) | synthetic |
| Isotope (abundance) | |
| Density g/cm3 | 19.84 |
| Van der Waals radius (pm) | 244 |
| Covalent radius (pm) | 173 |
| Electronegativity (Pauling) | 1.3 |
| Vaporization enthalpy (kJ/mol) | - |
| Enthalpy of fusion (kJ/mol) | 14.39 |
| Specific heat capacity (J/g·K) at 25ºC and 1 atm | - |
| Thermal conductivity (W/cm·K) at 25ºC and 1 atm | - |
| Oxidation state | +6, +5, +4, +3 |
| Electron affinity (eV) | |
| 1st Ionization potential (eV) | 5.9738 |
