Question

1. arrange the following elements in order of increasing ionization energy. a. be, mg, sr b. bi, cs, ba c. na, al, s

Explanation:

Step1: Recall ionization - energy trend

Ionization energy increases across a period and decreases down a group in the periodic table.

Step2: Analyze group - 2 elements (Be, Mg, Sr)

Be, Mg, Sr are in group 2. As we go down the group, ionization energy decreases. So the order is Sr < Mg < Be.

Step3: Analyze Bi, Cs, Ba

Cs is an alkali metal (group 1), Ba is an alkaline - earth metal (group 2), and Bi is in group 15. Cs has the lowest ionization energy as it is in group 1. Ba is in group 2 and Bi is in group 15. So the order is Cs < Ba < Bi.

Step4: Analyze Na, Al, S

Na, Al, S are in the same period (period 3). As we move from left to right across the period, ionization energy increases. So the order is Na < Al < S.

Answer:

a. Sr < Mg < Be
b. Cs < Ba < Bi
c. Na < Al < S