Oxygen is a chemical element with symbol (O) and atomic number 8. It is a member of the klaxane group in the periodic table, is a highly reactive nonmetal, and is an oxidizing agent that readily forms oxides with other compounds with most elements.
After hydrogen and helium, oxygen is the third most abundant element in the universe by mass. At standard temperature and pressure, the element’s two atoms form dioxygen with the formula O2 to form a colorless and odorless diatomic gas. Diatomic oxygen gases account for 20.95% of the Earth’s atmosphere. Oxygin makes up about half of the Earth’s crust in the form of oxides.
Deoxygen provides the energy released in combustion and aerobic cellular respiration, and many major classes of organic molecules in living organisms contain oxygen atoms, such as proteins, nucleic acids, carbohydrates, and fats, the major constituents of animal shells as inorganic compounds. In do, teeth, and bone. Most of the mass of organisms living as a component of water is oxygin, which is the major component of life.
Oxygen in Atmosphere
Oxygen in the Earth’s atmosphere is continuously replenished by photosynthesis , which is water and carbon dioxide. Uses the energy of sunlight to produce oxygen. Oxygen is very chemically reactive in order to remain a free element in the air without being constantly assigned by the photosynthetic action of living organisms. Oxygin, another form of ozone (O3) (allotrope), strongly absorbs ultraviolet UVB radiation and the high-altitude ozone layer helps protect the biofiber from ultraviolet radiation. However, ozone present on the surface is a byproduct of smog and thus a pollutant.
Discoverers of Oxygen
Oxygen was isolated by Michael Sendivogius before 1604, but it is generally believed that the element was discovered independently by Carl Wilhelm Scheele in Uppsala in 1773 or earlier, and in 1774 by Joseph Priestley in Wiltshire. Had. Priority is often given to Priestley since his work was first published. However, Priestley called oxygin “defloginative air”, and did not recognize it as a chemical element. The name oxygen was coined in 1777 by Antoine Lavoisier, who first recognized oxygen as a chemical element and correctly portrayed the role it played in combustion.
Common uses of oxygen include steel, plastic and textile production, brazing, welding and harvesting of steels and other metals, rocket propellant, oxygin therapy, and life support systems in aircraft, submarines, spaceflight and diving.
Physical properties of oxygen
Oxygen dissolves more easily in water than nitrogen, and in freshwater more easily than in seawater. About 1 molecule is dissolved for every 2 molecules of N2 (1: 2) compared to an atmospheric ratio of about 1: 4 in water in equilibrium with air. The solubility of oxygen in water is temperature dependent, and dissolves more than 20 ° C at about 0 ° C twice. At 25 ° C of air and 1 standard atmosphere (101.3 kPa), freshwater contains about 6.04 mL (mL) of oxygin per liter, and seawater contains about 4.95 mL per liter. At 5 ° C the solubility increases by 9.0 mL (more than 50% at 25 ° C) per liter of water and 7.2 mL (45% more) per liter for sea water.
Chemical properties of oxigen
At standard temperature and pressure (STP), the element’s two atoms bind dioxygen with the formula O2 to form a colorless, odorless, tasteless diatomic gas. Oxygen is a member of the chalcogen group on the periodic table and is a highly reactive nonmetal element. As such, it easily forms compounds (especially, oxides) with almost all other elements.
Oxygen is a strong oxidizing agent and has the second-highest electronegativity of all reactive elements, second only to fluorine. By mass, oxigen is the third most abundant element in the universe after hydrogen and helium, and the most abundant element in the earth’s crust by mass, which is about half of the mass of the crust.
Without the photosynthetic action of living beings, free oxigen is chemically reactive to appear on Earth, Which use the energy of sunlight to produce elemental oxygen from water. Elemental O2 began to accumulate in the atmosphere after the evolutionary form of photosynthetic organisms about 2.5 billion years ago. Diatomic oxygen gas is currently 20.8 percent of the volume of air.