The energy of the 2s state of some element is -5691ev

Question

a) The energy of the 2s state of some element is -5.691eV. Compute the value of Z_eff for this state.

b) The energy of the 4s state of some element is-4.339 eV. Compute the value of Z_eff for this state.

c) Compare Z_eff for the 2s state of lithium, the 3s state of sodium, and the 4s state if potassium. What trend do you see?

Z_eff becomes smaller going down the columns in the periodic table. Z_eff remains constant going up or down the columns in the periodic table. Z_eff becomes larger going down the columns in the periodic table.