Diamond crystal. Solid carbon comes in different forms known as allotropes depending on the type of chemical bond. The two most common allotropes of pure carbon are diamond and graphite. In graphite the bonds are sp orbital hybrids and the atoms form in planes with each bound to three nearest neighbors 120 degrees apart. In diamond they are sp and the atoms form tetrahedra with each bound to four nearest neighbors. Tetrahedra are rigid, the bonds are strong, and of all known substances diamond has the greatest number of atoms per unit volume, which is why it is both the hardest
ACS Award in Pure Chemistry award was first awarded in 1931, with Linus Pauling the inaugural recipient. It is sponsored by the Alpha Chi Sigma Fraternity and the Alpha Chi Sigma Educational Foundation. Source: American Chemical Society List of prizes, medals and awards ACS Award in Pure Chemistry The American Chemical Society Award in Pure Chemistry is awarded annually by the American Chemical Society (ACS) "to recognize and encourage fundamental research in pure chemistry carried out in North America by young men and women." "Young" means born within 35 years of the awarding of the Award, which takes place at the Spring meeting of the