61Pm[145]
Promethium
LanthanidesRare-earth metals used in strong magnets, phone screens and lasers.
[Xe] 4f⁵ 6s²
- Atomic number
- 61
- Atomic mass
- [145]
- Protons
- 61
- Neutrons
- 84
- Electrons
- 61
- Shells
- 2, 8, 18, 23, 8, 2
- State at 25 °C
- Solid
- Position
- Period 6, f-block
Proton (+)Neutron (0)Electron (−)
Discovered byJacob Marinsky, Lawrence Glendenin and Charles Coryell, 1945Jacob Marinsky, Lawrence Glendenin and Charles Coryell: 1 element
Found in uranium fission products and named after Prometheus, who stole fire from the gods.
Did you know?
- It has no stable isotopes.
- It is the only lanthanide with no stable form.
Where it's found
- Almost none in nature; made in reactors
What it's used for
- Long-life nuclear batteries
- Research
Try it
There's no safe home experiment for Promethium. Explore it with the animated atom above instead.