- Atomic Radius (Å)
Oxygen is a chemical element with symbol O and atomic number 8. It is a member of the chalcogen group on the periodic table and is a highly reactive nonmetal and oxidizing agent that readily forms compounds (notably oxides) with most elements. By mass, oxygen is the third-most abundant element in the universe, after hydrogen and helium.
8 Atomic Number
16 u Atomic Mass
50.5 K Melting Point
90.2 K Boiling Point
1.43 g/liter Density
0.65 Å Atomic Radius
0.66 Å Covalent Radius
3.44 Electronegativity
13.62 eV First Ionization Energy
140.98 Electron Affinity
2 Number of Shells
6 Electron Valency
2, 6 Electron Shell Occupations
0.92 J/g Specific Heat