Plutonium (symbol Pu, atomic number 94) is a synthetic actinide central to nuclear weapons and spacecraft power sources. It is classified as a actinide and sits in the actinide series (f-block), period 7 of the periodic table.
Overview
Plutonium is the chemical element with atomic number 94 and the symbol Pu. With a standard atomic weight of [244], it is a actinide. In the periodic table it occupies the actinide series (f-block) and period 7, and under standard conditions it is normally a solid. Plutonium is a synthetic actinide central to nuclear weapons and spacecraft power sources.
Atomic structure
An atom of Plutonium has 94 protons in its nucleus and, when neutral, 94 electrons arranged in the configuration [Rn] 5f6 7s2. Plutonium has no stable isotope; the value [244] refers to the mass number of its most stable or most commonly produced isotope.
Discovery and place in the table
Plutonium was discovered in 1940 by Glenn T. Seaborg et al.. It follows Neptunium (Np) and precedes Americium (Am) in order of atomic number.
| Atomic number | 94 |
|---|---|
| Symbol | Pu |
| Atomic mass | [244] |
| Category | Actinide |
| Group | — |
| Period | 7 |
| Electron configuration | [Rn] 5f6 7s2 |
| Phase at STP | Solid |
| Discovered | 1940 (Glenn T. Seaborg et al.) |