1 HYDROGEN - H

• Hydrogen is the simplest and most abundant element in the universe. It is the lightest and simplest chemical element, with an atomic number of 1 and symbol H. It is a colorless, odorless, and tasteless gas at standard temperature and pressure, and it is the most abundant element in the universe. Hydrogen has many applications, including being used as a fuel for rockets and as a key component in the production of ammonia for fertilizer.

  1. Physical properties: Hydrogen is a diatomic gas with a molecular formula of H2. It is a non-metal and is located in group 1 of the periodic table. It has a melting point of -259.2°C and a boiling point of -252.9°C.

  2. Chemical properties: Hydrogen is a highly reactive element that readily forms compounds with other elements. It can form covalent and ionic bonds, and it is a reducing agent. Hydrogen can react with oxygen to form water, with nitrogen to form ammonia, and with carbon to form methane.

  3. Isotopes: Hydrogen has three naturally occurring isotopes:

     1. protium (1H) - most common and stable isotope

     2. deuterium (2H) - radioactive

     3. tritium (3H) - radioactive

  4. Occurrence: Hydrogen is the most abundant element in the universe, making up about 75% of its elemental mass. It is found in the sun, stars, and other celestial bodies. On Earth, it is present in water, organic compounds, and in the atmosphere, although in very small amounts.

  5. Uses: Hydrogen has many practical applications, including in the production of ammonia for fertilizers, in refining petroleum and other fuels, as a fuel for rockets and spacecraft, in welding and cutting metals, and in fuel cells for generating electricity.