Naturally occurring heavy isotope of hydrogen, mass number 2 (one proton and one neutron), discovered by US chemist Harold Urey in 1932. It is sometimes given the symbol D. In nature, about one in every 6,500 hydrogen atoms is deuterium. Combined with oxygen, it produces heavy water (D2O), used in the nuclear industry.
The five points of the star represent the unity of farmers, workers, intellectuals, soldiers, and youth in establishing socialism. Red stands for revolution and bloodshed. Effective date: 2 July 1976.