Question 6.10: Using only the periodic table, rank the following elements i......
Using only the periodic table, rank the following elements in order of increasing ionization energy: Br, F, Ga, K, and Se.
Strategy We want to arrange the elements from the smallest ionization energy to the largest. Begin by finding each element in the periodic table. Then use the general trends for ionization energy to place them in the requested order.
Ionization energy increases as we go up or to the right in the periodic table. From our list of elements, all but fluorine are in the fourth period. So we expect their ionization energies to increase from left to right: K < Ga < Se < Br. Finally, fluorine lies above bromine in Group 17, so it will have the largest ionization energy. This gives us the requested order: K < Ga < Se < Br < F.
Check Your Understanding Using only the periodic table, rank the following elements in order of increasing ionization energy: He, Mg, N, Rb, and Si.