Classification of Plutonium
Plutonium (Pu) is a radioactive chemical element classified as an actinide metal. It is a transuranic element, meaning it has an atomic number greater than that of uranium, and is not found naturally in significant quantities on Earth. It was first synthesized in a laboratory.
Physical Appearance and State
At room temperature (approximately 25 °C), Plutonium exists as a solid. When freshly prepared, it appears silvery-white, exhibiting a metallic luster. However, it readily oxidizes upon exposure to air, forming a dull grey, greenish-yellow, or olive-green tarnish on its surface. Plutonium is known to be a hard but brittle metal, displaying varying densities across its multiple allotropic forms.
Thermal Properties
Plutonium has a relatively low melting point for a metal, but a high boiling point.
- Melting Point: Approximately 640 °C
- Boiling Point: Approximately 3228 °C