Skip to content

ChemistryEdu Logo Group 16 Elements | Physical Properties and Oxidation States#

Physical Properties of Group 16 Elements#

1. Type:#

  • Oxygen and sulphur are non metals.
  • Selenium and tellurium are Metalloids.
  • Polonium is a metal and is a radioactive element.

2. Melting and boiling points:#

  • Boiling and melting points increase with an increase in atomic number down the group.
  • The large difference between the melting and boiling points of oxygen and sulphur may be explained on the basis of their atomicity: oxygen exists as diatomic molecule (O2) whereas sulphur exists as polyatomic molecule (S8).
  • The elements of Group 16 exhibit a number of Oxidation states.
  • The stability of -2 oxidation state decreases down the group.
  • Since electronegativity of oxygen is group. high, it shows only negative oxidation states -2 except in the case of OF2 where it shows +2 oxidation state.
  • Other elements of the group exhibit oxidation states of +2, +4 and +6.
  • Sulphur (s), Selenium (se), Tellurium (Te) usually exhibit +4 oxidation state in their compounds with oxygen and +6 with fluorine.
  • The stability of + 6 oxidation state decreases down the group and that of +4 oxidation state increases due to inert pair effect.
  • Bonding in +4 and +6 oxidation states is primarily covalent.

Anomalous Behaviour of Oxygen#

  • Oxygen shows anomalous behaviour in its group due to its small size, high electronegativity and non-availability of d-orbitals in its valence shell.
  • One typical example of effects of small size and high electronegativity is the presence of strong hydrogen bonding in H2O which is not found in and H2S.