HELIUM - He

  • Helium is the second lightest element and is the second most abundant element in the universe. It has the symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, and inert gas that heads the noble gas series in the periodic table. Helium is used for a variety of purposes, including in balloons, as a coolant in MRI machines, and in welding and cutting applications.

    1. Physical properties: Helium is a gas at room temperature and pressure, and it has a boiling point of -268.9°C and a melting point of -272.2°C. It is lighter than air, and it has a low density and low solubility in water.

    2. Chemical properties: Helium is an inert gas and does not readily form chemical compounds with other elements. It has the lowest boiling point of all elements and is the second-lightest element, after hydrogen.

    3. Isotopes: Helium has two stable isotopes:

      1. helium-3: rare 1 ppm of natural helium

      2. helium-4: most common isotope and accounts for almost all natural helium

    4. Occurrence: Helium is found in natural gas deposits, and it is extracted by liquefying natural gas and separating the helium by fractional distillation. It is also found in the atmosphere of the sun and other stars.

    5. Uses: Helium has many practical applications, including in cryogenics, welding, leak detection, and as a lifting gas for balloons and airships. It is also used in gas chromatography, as a coolant in nuclear reactors, and in medical imaging.

    6. Helium is made from fusing two hydrogen atoms together under high pressure and temperatures within stars.

    • Helium typically couples with two electrons (-2) making it a very unreactive Noble Gas, the first of the Noble Gases found on the far right side of the periodic table.