8 OXYGEN - O
Oxygen is the third most abundant element in the universe. It makes up about 21% of the Earth's atmosphere and is used by many organisms for respiration. Oxygen is also used in many industrial processes, including the production of steel and the treatment of wastewater.
Oxygen is a chemical element with the symbol O and atomic number 8. It is a member of group 16 of the periodic table, also known as the chalcogens.
Physical Properties: Oxygen is a colorless, odorless, and tasteless gas at room temperature. It has a boiling point of -183°C and a melting point of -218°C. Oxygen is slightly denser than air and is slightly soluble in water.
Chemical Properties: Oxygen is a highly reactive element and readily forms compounds with most other elements. It is a non-metal and typically forms covalent bonds with other non-metals. Oxygen is a strong oxidizing agent and can react with many organic and inorganic substances. It is essential for respiration and combustion processes.
Atomic Properties: Oxygen has an atomic mass of 15.999 u. It has 8 protons and 8 electrons in its neutral state. Oxygen has three stable isotopes: 16O, 17O, and 18O.
Occurrence: Oxygen makes up about 21% of the Earth's atmosphere. It is also found in many minerals and compounds, such as water (H2O) and carbon dioxide (CO2). Oxygen is an essential element for life, as it is a key component of many biological molecules, including DNA, proteins, and carbohydrates.
Along with carbon, Oxygen forms as a the byproduct of the collapse of stars, representing four helium cores fused together.