p-Block Elements — Nitrogen, Oxygen, Halogen and Noble Gas Families

p-Block groups 15-18 at PGT depth: nitrogen family (NH₃, HNO₃, allotropes, oxides); oxygen family (O₂, O₃, H₂O₂, sulphur allotropes, H₂SO₄); halogens (reactivity, HX, oxoacids, displacement); and noble gases (inertness, Xe compounds).