Selenium
| Basic Information | Crystal Structure | Isotope | Facts | Related Links |
| Symbol: | Se |
| Atomic Number: | 34 |
| Atomic weight: | 78.96u |
| Melting Point: | 494K |
| Boiling Point: | 958K |
| Number of Protons/Electrons: | 34 |
| Number of Neutrons: | 45 |
| Classification: | Non-metal |
| Crystal Structure: | Hexagonal |
| Density at 293 K: | 4.8g/mL |
| Color: | Gray |
| Bonding radius: | 1.16A |
| Atomic radius: | 1.22A |
| Ionization Potential: | 9.752V |
| Electronegativity: | 2.55 |
| Heat of vaporization: | 37.7kJ/mol |
| Heat of fusion: | 6.694kJ/mol |
| Specific heat: | 0.32J/gK |
| Electron configuration: | [Ar]3d104s24p4 |
Crystal Structure
| Isotope | Half Life |
| Se73 | 7.15 hours |
| Se74 | Stable |
| Se75 | 119.78 days |
| Se76 | Stable |
| Se77 | Stable |
| Se78 | Stable |
| Se79 | 65000 years |
| Se80 | Stable |
| Se82 | Stable |
| Date of Discovery: | 1817 |
| Discoverer: | Jons Berzelius |
| Uses: | photoelectric cells, TV cameras |
| Obtained From: | refining of lead, copper, nickel |