The chemical element with atomic number 8 and symbol O is called oxygen. It belongs to the chalcogen group of the periodic table, is a very reactive nonmetal and an oxidizing agent that readily produces oxides with most elements as well as other compounds. After hydrogen and helium, oxygen is the third most abundant element in the universe and the most abundant element on Earth. Two atoms of the element combine to form O at normal temperature and pressure.2 It forms dioxygen, a colorless and odorless diatomic gas with the formula Earth's atmosphere currently consists of 20,95% diatomic oxygen gas, although this ratio has fluctuated significantly over a very long period of time. Oxygen in its oxide form makes up more than half of the Earth's crust.
The major component inorganic compounds of animal shells, teeth, and bone, as well as a few basic types of organic molecules found in living organisms, such as proteins, nucleic acids, carbohydrates, and lipids, all contain oxygen atoms. Since water is the primary component of all life forms, oxygen makes up the majority of the mass of all living things. Photosynthesis, which uses the energy of sunlight to create oxygen from water and carbon dioxide, constantly replenishes the amount of oxygen in the Earth's atmosphere. Oxygen, which is not constantly renewed by the photosynthetic activities of living organisms, is too chemically reactive to be a free element in the air. Ozone (O) is an additional form (allotrope) of oxygen.3), is a strong absorber of ultraviolet (UVB) light, and the high-altitude ozone layer contributes to the protection of the biosphere from UV radiation.
But ozone on the surface is a pollutant as it is a result of smoky air.
Although Michael Sendivogius isolated oxygen before 1604, it is generally accepted that Joseph Priestley of Wiltshire and Carl Wilhelm Scheele of Uppsala independently identified the element in 1774. Priestley is often preferred because it was his work that was first published. Priestley, on the other hand, did not classify oxygen as a chemical element and instead referred to it as "dephlogisticated air". Antoine Lavoisier first identified oxygen as a chemical element and correctly described the function it plays in combustion; he also named it oxygen in 1777.
Common uses for oxygen are the manufacture of steel, plastics and textiles, brazing, welding and cutting of steel and other metals, the use of oxygen as a rocket propellant, oxygen therapy, and life support systems for airplanes, submarines, space travel and diving.
📩 13/01/2023 14:17