How Do You Determine First Ionization Energy?

By Staff WriterLast Updated Mar 28, 2020 12:57:34 PM ET

To determine first ionization energy, one must know the element being used. First ionization energy shows periodically through the table of elements in a repetitive pattern. First ionization energy is the amount of energy required to remove an electron from one mole of gaseous atoms to produce one mole of gaseous ions with a positive charge.

  1. Find the charge of the nucleus

    The more protons there are in the nucleus, the stronger the attraction of the electrons. Therefore, a greater first ionization energy is needed as the nucleus becomes more positively charged.

  2. Find the distance between the electron and the nucleus

    No matter the charge of a nucleus, if the electron is far enough away, its attraction is much weaker; thus, the first ionization energy is smaller.

  3. Determine the location of the electron

    Electrons in the outer layer feel a smaller net pull than one in the inner layer, and therefore, they require a smaller ionization energy. This is because the inner layer of electrons shields the outer electrons from the attraction of the nucleus.

  4. Determine whether it is a single or paired electron

    Paired electrons actually require less energy to remove than a single electron because they tend to repulse each other.