98 - Californium actinide
Discovered by Lawrence Berkeley Laboratory in 1950
- Atomic Radius (Å)
Californium is a radioactive metallic chemical element with symbol Cf and atomic number 98. The element was first made in 1950 at the University of California Radiation Laboratory in Berkeley, by bombarding curium with alpha particles (helium-4 ions). It is an actinide element, the sixth transuranium element to be synthesized, and has the second-highest atomic mass of all the elements that have been produced in amounts large enough to see with the unaided eye (after einsteinium).
Shell | Electrons | Orbitals |
---|---|---|
1 | 2 | 2 in 1s |
2 | 8 | 2 in 2s + 6 in 2p |
3 | 18 | 2 in 3s + 6 in 3p + 10 in 3d |
4 | 32 | 2 in 4s + 6 in 4p + 10 in 4d + 14 in 4f |
5 | 28 | 2 in 5s + 6 in 5p + 10 in 5d + 10 in 5f |
6 | 8 | 2 in 6s + 6 in 6p |
7 | 2 | 2 in 7s |
251 u
Atomic Mass
1173 K
Boiling Point
15.1 g/cm³
Density
-9.73e+1
Electron Affinity
1.3
Electronegativity
6.28 eV
First Ionization Energy
1925.15 K
Melting Point
7
Number of Shells
98
Atomic Number
2, 8, 18, 32, 28, 8, 2
Electron Shell Occupations