Oxygen is a chemical substance and its symbol is O. Oxygen is a non-metal and present as a diatomic. The normal phase of oxygen is gas. The atomic number or atomic mass of oxygen are 8 and 16 respectively. There are 8 electrons present in an atom of oxygen. The number of electrons per shell of oxygen atom are 2 and 6. The electronic configuration of oxygen is 1s2 2s2 2p4. The melting and boiling points of oxygen are 54.36 kelvin and 90.20 kelvin respectively. Oxygen is placed in 16th group and 2nd period of periodic table. Moreover, the valence electrons is present in p-orbital so, it is present in p-block of periodic table.