Chemical element of an element to exist in one of many structural forms is known as 'allotropy'. The standard state, also known as the reference state, of an element is defined as its thermodynamically most stable state at a pressure of 1 bar and a given temperature (typically at 298.15 K). In thermochemistry, an element is defined to have an enthalpy of formation of zero in its standard state. For example, the reference state for carbon is graphite, because the structure of graphite is more stable than that of the other allotropes. Several kinds of descriptive categorizations can be applied broadly to
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