Oxygen [O] CAS-ID: 7782-44-7 An: 8 N: 8 Am: 15.9994 (3) g/mol Group No: 16 Group Name: Chalcogen Block: p-block Period: 2 State: gas at 298 K Colour: colourless as a gas, liquid is pale blue Classification: Non-metallic Boiling Point: 90.2K (-182.9°C) [...]