Cf
Californium
Atomic number: 98Mass: 251 uCategory: Actinide
About Californium
Californium is a radioactive chemical element. It is a powerful neutron emitter. It was named after California, USA. One microgram of californium-252 emits 170 million neutrons per minute.
Properties
Period
7
Group
N/A
Block
F
Category
Actinide
Electronegativity
1.30 (Pauling)
Ionization Energy
608 kJ/mol
Melting Point
1173 K (900°C)
Boiling Point
1743 K (1470°C)
Density
15.1 g/cm³
Oxidation States
+3
Electron Configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 6s² 6p⁶ 5f¹⁰ 7s²
[Rn] 5f¹⁰ 7s²
Shell 1:2e⁻
Shell 2:8e⁻
Shell 3:18e⁻
Shell 4:32e⁻
Shell 5:28e⁻
Shell 6:8e⁻
Shell 7:2e⁻
Real-World Uses
Nuclear reactor startup neutron sources
Cancer radiotherapy
Gold/silver ore detection
Moisture gauges
Studying nuclear fission
Fun Fact
A single gram of californium-252 costs about $27 million — making it one of the most expensive substances on Earth!