Answer:
Inverse
Explanation:
Several facts are required to answer this question properly:
- the greater the atomic radius, the greater the distance is between the nucleus and the valence electrons;
- according to the Coulomb's law, force is inversely proportional to distance, this means that the greater the atomic radius, the lower the attraction force is between the nucleus and the valence electrons;
- ionization energy is the energy required to remove a valence electron;
- a greater amount of energy would be required to overcome a greater force.
From the statements above, we may conclude that the greater the atomic radius (and, thus, the lower the attraction force between the valence electrons and the nucleus), the lower the ionization energy (due to the fact that a lower amount of energy is required to overcome a weaker force).
This means ionization energy is inversely proportional to atomic radius.
