The Photoelectric Effect

Ekinetic = Ephoton - εwork

Metal εwork (eV)
K 2.29
Na 2.36
Ca 2.87
Li 2.9
Mg 3.66
Pb 4.25
Ga 4.32

Question
Light with photon energy 5.02 eV shines on a sample of metal. Photoelectrons with kinetic energy 1.36 eV are ejected. What is the chemical symbol of the metal?
Your answer: