In group 16 silicon dioxide is often a quite common compound that greatly takes place as sand or quartz. SiO2 is tetrahedral with Every silicon atom surrounded by 4 oxygen atoms. Several crystalline forms exist While using the tetrahedra associated with variety a polymeric chain. Illustrations are tridymite and cristobalite. https://boron-nitride59369.blogocial.com/an-unbiased-view-of-3d-utskrifter-metall-74713816