Final answer:
Ionization energy generally decreases as you go down a family on the periodic table because valence electrons are further away from the nucleus, leading to a weaker electrostatic pull and making ionization easier.
Step-by-step explanation:
According to Coulomb's law and the trend of ionization energy demonstrated in the periodic table, the correct answer is B) Ionization energy generally decreases. When we look at a family (or group) down the periodic table, ionization energy decreases because the atomic size increases as the n level of the valence electrons becomes larger. The increase in atomic size results in the valence electrons being further away from the nucleus and experiencing less electrostatic pull, which makes it easier to remove an electron from a larger, higher energy orbital. Thus, lesser energy is required to ionize atoms down a group.