In group 16 silicon dioxide is actually a very common compound that commonly takes place as sand or quartz. SiO2 is tetrahedral with each silicon atom surrounded by 4 oxygen atoms. Many crystalline types exist With all the tetrahedra associated with variety a polymeric chain. Illustrations are tridymite and cristobalite. https://devinfqajs.wikibyby.com/1984766/an_unbiased_view_of_3d_utskrifter_metall