In group 16 silicon dioxide can be a quite common compound that commonly takes place as sand or quartz. SiO2 is tetrahedral with each silicon atom surrounded by 4 oxygen atoms. Many crystalline kinds exist Along with the tetrahedra associated with kind a polymeric chain. Illustrations are tridymite and cristobalite. https://simonoonkh.blogzet.com/the-5-second-trick-for-magnezijum-stearat-uloga-53598400