The energy of an electron in a one-electron atom or ion equals (–2.18 x 10^–18 J) (Z²/n²). Estimate the ionization energy for the valence electron of the Li atom and compare it to its theoretical value of 520 kJ/mol.

(b) Which element in the periodic table has the largest ionization energy? Which has the smallest?

Based on their positions in the periodic table, predict which atom of the following pairs will have the smaller first ionization energy: (a) Br, Kr (b) C, Ca (c) Li, Rb (d) S, Ge (e) Al, B.

Choose the element with the higher first ionization energy from each pair. d. P or Sn