2-15 The ionization energy E₁ of the first three elements are: Ꮓ 1 2 3 Element H He Li EI 13.6 eV 24.6 eV 5.4 eV (a) Explain qualitatively the change in E₁ from H to He, Li. (b) What is the second ionization energy of He that is the energy required to remove the second electron after the first one is removed?