Oxygen and sulfur are both located in Group 16 (also known as the chalcogens) of the periodic table. Elements in the same group share similar chemical properties due to the presence of the same number of valence electrons.

Both oxygen and sulfur have six valence electrons and tend to gain two electrons to achieve a stable electron configuration. This makes them highly reactive and forms covalent bonds with other elements to complete their outer shell.

They commonly participate in covalent bonding to complete their outer electron shells and demonstrate non-metallic properties. Oxygen and sulfur exist in various allotropic forms, with oxygen having two stable isotopes and sulfur having four stable isotopes.

Moreover, oxygen and sulfur display a gradual increase in their atomic and molecular sizes as one moves down the group, resulting in a decrease in electronegativity and ionization energy.