Chemistry

Question Analysis
This question involves comparing first ionization energies of noble gases. The main focus is on applying the basic group trend to a specific family of elements.

Key Concept Explanation
Noble gases all have full valence electron shells, making their ionization energies very high. However, down a group, atomic radius increases as electron shells are added. Valence electrons are farther from the nucleus and easier to remove, so ionization energy decreases down the group.

Step-by-Step Solution
1. All options are noble gases (Group 18).
2. Their positions from top to bottom in the group: He → Ne → Ar → Kr.
3. Apply the group trend: ionization e...