2.38 In each of the following pairs, pick the element with the higher ionization energy and explain your choice. a. Fe, Ru b. P. S C. K. Br d. C. N e. Cd,In f. Cl,F

a. Fe, Ru: Iron (Fe) has a higher ionization energy than Ruthenium (Ru). Ionization energy generally increases across a period from left to right on the periodic table. Since Fe is to the left of Ru in the same period, it has a higher ionization energy.<br /><br />b. P, S: Phosphorus (P) has a higher ionization energy than Sulfur (S). Ionization energy generally increases across a period from left to right on the periodic table. Since P is to the left of S in the same period, it has a higher ionization energy.<br /><br />c. K, Br: Potassium (K) has a lower ionization energy than Bromine (Br). Ionization energy generally increases across a period from left to right on the periodic table. Since K is to the left of Br in the same period, it has a lower ionization energy.<br /><br />d. C, N: Nitrogen (N) has a higher ionization energy than Carbon (C). Ionization energy generally increases across a period from left to right on the periodic table. Since N is to the right of C in the same period, it has a higher ionization energy.<br /><br />e. Cd, In: Indium (In) has a lower ionization energy than Cadmium (Cd). Ionization energy generally increases across a period from left to right on the periodic table. Since In is to the left of Cd in the same period, it has a lower ionization energy.<br /><br />f. Cl, F: Fluorine (F) has a higher ionization energy than Chlorine (Cl). Ionization energy generally increases across a period from left to right on the periodic table. Since F is to the right of Cl in the same period, it has a higher ionization energy.