IV A Group has 4 valence electrons and are arranged as \\\\(ns^2\\\\) \\\\(np^2\\\\).Onyx is the amorphous form of silica.Diamond is one of the hardest materials due to the strong covalent bonds which connect various atoms in the lattice.Graphite is used as a lubricant due to the weak bonding between its layers, which allows the layers to slide on one another.