Oxygen (O) - Element 8 | Properties & Electron Configuration
What is Oxygen?
Oxygen (O) is element 8, a nonmetal in period 2, group 16. Its electron configuration is 1s² 2s² 2p⁴.
| Atomic Number | 8 |
| Symbol | O |
| Atomic Mass | 15.999 u |
| Category | Nonmetal |
| Period | 2 |
| Group | 16 |
| Block | p |
| Electron Configuration | 1s² 2s² 2p⁴ |
| Short Config | [He] 2s² 2p⁴ |
| Electronegativity | 3.44 |
| Atomic Radius | 73 pm |
| Ionization Energy | 1314 kJ/mol |
| Electron Affinity | 141 kJ/mol |
| Phase (STP) | Gas |
Electron Configuration
The full electron configuration of Oxygen is 1s² 2s² 2p⁴. In noble gas shorthand, this is written as [He] 2s² 2p⁴.
Oxygen is a p-block element in group 16, period 2.
Periodic Trends
Electronegativity: Oxygen has a Pauling electronegativity of 3.44. Within group 16, electronegativity generally decreases down the group.
Atomic Radius: 73 pm. Across period 2, atomic radius generally decreases left to right as nuclear charge increases.
Ionization Energy: 1314 kJ/mol. Ionization energy generally increases across a period and decreases down a group.
View all 118 elements with trend overlays for electronegativity, atomic radius, ionization energy, and electron affinity.
Explore Oxygen on the Interactive Periodic TableRelated Topics
Sulfur (S)
Properties of Sulfur - same group as Oxygen
Selenium (Se)
Properties of Selenium - same group as Oxygen
Tellurium (Te)
Properties of Tellurium - same group as Oxygen
Lithium (Li)
Properties of Lithium - same period as Oxygen
Beryllium (Be)
Properties of Beryllium - same period as Oxygen
Boron (B)
Properties of Boron - same period as Oxygen