What is the predicted order of first ionization energies from highest to lowest for lithium (Li), sodium (Na), potassium (K), and rubidium (Rb) ?

Rb > K > Na > Li

K > Rb > Na > Li

Li > Na > K > Rb

Rb > K > Li > Na

Rb > K > Na > Li

Explanation:

Ionization energy increases up the period and up the group.

From the periodic table, we can see that Li is the going to have the highest ionization energy and Rb is going to have the lowest.

Therefore, the correct answer is the first choice