Se
Selenium
Element 34 · 78.971 u
Selenium is an essential trace element used in electronics and dietary supplements.
Fisiese eienskappe
| Atomic Mass | 78.971 u |
| Density | 4.809 g/cm³ |
| Smelt punt: | 494.0 K |
| Boiling Point | 958.0 K |
| Appearance | Red to gray, black in vitreous form |
| Toestand by kamerkomp | Solied |
Chemical Properties
| Electronegativity | 2.55 (TrinidadCity name (optional, probably does not need a translation)) |
| 1st Ionization Energy | 941.0 kJ/mol |
| Electron Affinity | 195.0 kJ/mol |
| Oxidation States | -2, +2, +4, +6 |
Atomic Properties
| Electron Configuration | [Ar] 3d10 4s2 4p4 |
| Atomic Radius | 103.0 pm |
| Covalent Radius | 120.0 pm |
| Atomic radius: | 190.0 pm |
Discovery
| Discovered By | Jons Jacob Berzelius |
| Discovery Year | 1817 |
| Location | Stockholm, Sweden |
| Genoemde Na | Greek 'selene' meaning moon |
About Selenium
Selenium has properties between sulfur and tellurium. Its conductivity changes with light, making it useful in photoconductors. It is an essential trace element as a component of selenocysteine.
Gebruiks & Programme
Photovoltaic cells, photocopiers, glass manufacturing, dietary supplements, and semiconductors.
Fun Fact
Selenium is essential in tiny amounts but toxic in larger doses. Brazil nuts are the richest known dietary source.
Isotopes
| Definieer Molekulêr Gewigte | Abundance | Half-Life | Stabiel |
| 76 | 0.0937% | - | Ja |
| 78 | 0.2377% | - | Ja |
| 80 | 0.4961% | - | Ja |
| 82 | 0.0873% | - | Ja |
Electron Configuration
[Ar] 3d10 4s2 4p4