The oxygen family (Group 16) is also known as the chalcogen family.
Oxygen family – Chalcogen
The oxygen family consists of the elements that make up group 16 on the periodic table: oxygen, sulphur, selenium, tellurium, and polonium. These elements all have six electrons in their outermost energy level, accounting for some common chemical properties. Oxygen is a colourless, odourless, tasteless gas with a melting point of −218°C (−360°F) and a boiling point of −183°C (−297°F).
Physical properties of chalcogens
- The general electronic configuration of the chalcogens can be written as ‘ns2np4.
- The chalcogen with the lowest atomic radius and ionic radius is oxygen, whereas the chalcogen with the largest atomic/ionic radius (excluding livermorium) is polonium.
- The ionization enthalpies of the chalcogens decrease while progressing down the group. Oxygen has the highest ionization enthalpy among the chalcogens.
- The electron gain enthalpies of the chalcogens decrease down the group.
- Oxygen and sulphur are classified as non-metals.
- The most electronegative chalcogen is oxygen, and the least electronegative chalcogen is polonium (livermorium not considered).
Chemical properties of chalcogens
- The most common allotropes of oxygen are dioxygen and ozone. In fact, oxygen has 9 known allotropes. Furthermore, sulphur is known to have over 20 known allotropes.
- The regular oxidation states shown by the chalcogens include -2, +2, +4, and +6.
- When reacted with dihydrogen, the chalcogens usually form hydrides with the general formula H2M (where M denotes any chalcogen – oxygen, sulphur, selenium, tellurium, or polonium).