Chemistry

Question Analysis
This question assesses the understanding of the factors that influence ionization energy, specifically the role of atomic radius.

Key Concept Explanation
Ionization energy is inversely related to atomic radius. As the atomic radius increases, the distance between the nucleus and the outermost electrons increases, weakening the nuclear attraction and making it easier to remove an electron.

Step-by-step Solution
1. Identify the elements given: Potassium (K) and Calcium (Ca).
2. Recall that Potassium (K) is in Group 1A and Calcium (Ca) is in Group 2A.
3. Potassium has a larger atomic radius than calcium because calcium’s higher effective nuclear charge pulls electrons closer to ...