I have a question asking, "which pair of elements is listed in order of decreasing first ionization energy? a)Na,Mg b)Mg,Al c)Al,Si d)Si,P "
I know the answer is B, can anyone explain why?

Question

I have a question asking, "which pair of elements is listed in order of decreasing first ionization energy? a)Na,Mg  b)Mg,Al  c)Al,Si   d)Si,P "
I know the answer is B, can anyone explain why?

anonymous · Answer

"The ionization energy (IE) of an atom or molecule describes the minimum amount of energy required to remove an electron (to infinity) from the atom or molecule" WIki


        1st ionization energy

            X → X+ + e-"

        2nd ionization energy

            X+ → X2+ + e-

        3rd ionization energy

            X2+ → X3+ + e-"Wiki

anonymous · Answer

Von is giving useful information, but not related to the question you are asking.

Identify the trends in first ionization energy down a group and across a period,  Once you know the trends, look at the periodic table and see where each pair of elements are located, to work out the best answer.