Photosynthesis Earth's atmosphere, and supplies all of the organic compounds and most of the energy necessary for life on Earth. Although photosynthesis is performed differently by different species, the process always begins when energy from light is absorbed by proteins called reaction centres that contain green chlorophyll pigments. In plants, these proteins are held inside organelles called chloroplasts, which are most abundant in leaf cells, while in bacteria they are embedded in the plasma membrane. In these light-dependent reactions, some energy is used to strip electrons from suitable substances, such as water, producing oxygen gas. The hydrogen freed by the splitting
Liquid nitrogen a byproduct of manufacture of liquid oxygen used for industrial processes such as steelmaking. Liquid-air plants producing on the order of tons per day of product started to be built in the 1930s but became very common after the Second World War; a large modern plant may produce 3000 tons/day of liquid air products. Liquid nitrogen Liquid nitrogen is nitrogen in a liquid state at an extremely low temperature. It is a colorless clear liquid with a density of 0.807 g/ml at its boiling point () and a dielectric constant of 1.43. Nitrogen was first liquefied at the Jagiellonian University