Quick Facts
| Property | Value |
|---|---|
| Symbol | U |
| Atomic Number | 92 |
| Atomic Mass | 238.03 u |
| Category | Actinide |
| Period | 7 |
| Group | 3 |
| Block | f |
| Electron Configuration | [Rn] 5f³ 6d¹ 7s² |
Physical Properties
| Property | Value |
|---|---|
| State at 20°C | Solid |
| Density | 19.1 g/cm³ |
| Melting Point | 1135°C (1408 K) |
| Boiling Point | 4131°C (4404 K) |
| Appearance | Silvery-gray metal |
History and Discovery
Discovered by: Martin Heinrich Klaproth Year of Discovery: 1789 Location: Berlin, Germany
Etymology
Named after the planet Uranus, discovered 8 years earlier.
Applications and Uses
- Nuclear power generation (U-235)
- Nuclear weapons
- Armor-piercing ammunition (depleted uranium)
- Dating rocks (uranium-lead dating)
- Historically: pottery glazes
Interesting Facts
- Naturally fissile—the basis of nuclear energy
- Only 0.7% of natural uranium is fissile U-235
- Named after Uranus, which was named after a god
- One kilogram of U-235 releases energy equivalent to 20,000 tons of TNT
- First nuclear chain reaction achieved in 1942 (Manhattan Project)