# Ionization energy and Z effective

1. Nov 28, 2011

### fluidistic

1. The problem statement, all variables and given/known data
Consider an alkali atom in its fundamental state and assume that its valence electron experiment a constant shielding with $Z_{eff}>1$. Use the tabulated values of the ionization energy to estimate $Z_{eff}$ for the Li, Na and K atoms.

2. Relevant equations
I do not know.

3. The attempt at a solution
Z effective is the effective charge (in units of electron charge) the valence electron feels. I've "cheated" and checked out Z effective and the ionization energies for all these atoms, yet I do not find any correlation.
Ionization energies: (5.39, 5.14, 4.34) eV.
Z effective: (1.25, 1.84, 2.26).
I'm at a loss. Any tip is appreciated.