16.3 Sulfur and related compounds 1.Elemental sulfur:a few allotropic forms rhombic sulfur monoclinic sulfur plastic sulfur (斜方硫) (单斜硫) (弹性硫) density/g'cm3 2.06 1.99 color yellow buff fast cooling of liquid (浅黄) sulfur heated above stability <94.5℃ >94.5℃ 190℃ Structure: a puckered Sa ring structure S:sp3 hybridization for both斜方硫and单斜硫rhombic sulfur monoclinic sulfur plastic sulfur (斜方硫) (单斜硫 ) (弹性硫) density/gcm-3 2.06 1.99 color yellow buff fast cooling of liquid (浅黄) sulfur heated above stability < 94.5℃ > 94.5℃ 190℃ 1. Elemental sulfur: a few allotropic forms 16.3 Sulfur and related compounds Structure： S：sp3 hybridization for both 斜方硫 and 单斜硫 a puckered S8 ring structure