94Pu244.06420
Plutonium
Actinide
Solid at STP
Period 7Block FDiscovered 1940
[Rn]7s2 5f6
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.
📖 Read more on Wikipedia →Atomic Properties
| Atomic Number | 94 |
| Atomic Mass | 244.06420 u |
| Electron Configuration | [Rn]7s2 5f6 |
| Oxidation States | +6, +5, +4, +3 |
| Electronegativity | 1.28 (Pauling) |
| Atomic Radius | 243 pm |
| Ionization Energy | 6.06 eV |
| Block | F |
Physical Properties
| Appearance | silvery white, tarnishing to dark gray in air |
| Standard State | Solid |
| Melting Point | 913 K (639.9 °C) |
| Boiling Point | 3501 K (3227.8 °C) |
| Density | 19.84 g/cm³ |
| Molar Heat | 35.5 J/(mol·K) |
| CPK Color | #006BFF |
Classification
| Category | Actinide |
| Group Block | Actinide |
| Period | 7 |
| Block | F |
Discovery
| Year Discovered | 1940 |
| Discovered By | Glenn T. Seaborg |
| Electron Shells | 2, 8, 18, 32, 24, 8, 2 |