98Cf[251]
Californium
ActinidesHeavy, radioactive metals. Most of them are made only in laboratories.
[Rn] 5f¹⁰ 7s²
- Atomic number
- 98
- Atomic mass
- [251]
- Protons
- 98
- Neutrons
- 153
- Electrons
- 98
- Shells
- 2, 8, 18, 32, 28, 8, 2
- State at 25 °C
- Solid
- Position
- Period 7, f-block
Proton (+)Neutron (0)Electron (−)
Discovered byStanley Thompson, Kenneth Street, Albert Ghiorso and Glenn Seaborg, 1950Albert Ghiorso: 12 elementsGlenn T. Seaborg: 10 elementsStanley G. Thompson: 5 elements
Made at Berkeley and named after California.
Did you know?
- A single gram of californium-252 gives off trillions of neutrons every second.
- Californium was the target used to make element 118.
Where it's found
- Made in nuclear reactors
What it's used for
- Starting up nuclear reactors
- Finding oil and gold layers underground
- Detecting explosives
Try it
There's no safe home experiment for Californium. Explore it with the animated atom above instead.