94 - Plutonium actinide
Discovered by Glenn Seaborg in 1940
Plutonium is a transuranic radioactive chemical element with symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, and forms a dull coating when oxidized. The element normally exhibits six allotropes and four oxidation states.
Periodic table
| 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 | 24 | 2 in 5s + 6 in 5p + 10 in 5d + 6 in 5f |
| 6 | 8 | 2 in 6s + 6 in 6p |
| 7 | 2 | 2 in 7s |
Electron shells
silvery white, tarnishing to dark gray in air Appearance
244 u Atomic Mass
3.5k K Boiling Point
8 Group
4 Common Oxidation States
1.87 Å Covalent Radius
19.8 g/cm³ Density
−48.3 kJ/mol Electron Affinity
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f6 Electron Configuration
[Rn] 5f6 7s2 Electron Configuration (semantic)
1.28 Electronegativity
94 Electrons
6.03 eV First Ionization Energy
584.7 kJ/mol Ionization Energies
913 K Melting Point
43 Mendeleev Number
35.5 J/(mol·K) Molar Heat
7 Number of Shells
150 Neutrons
94 Atomic Number
163 Number of Isotopes
3, 4, 5, 6, 7 Oxidation States
7 Period
Solid Phase
94 Protons
2, 8, 18, 32, 24, 8, 2 Electron Shell Occupations