Chemistry

Question Analysis
This question involves applying group trends to the noble gases (Group 18). The main focus is on identifying the noble gas with the highest IE and the structural reason for this.

Key Concept Explanation
Noble gases have full valence shells, so they have very high ionization energies. Down Group 18, atomic radius increases, shielding strengthens, and IE decreases. Helium is the smallest noble gas (only 1 electron shell) with no inner electron shielding, so it has the strongest nuclear attraction for its valence electrons and the highest IE of all noble gases.

Step-by-Step Solution
1. Recall Group 18 IE trend: decreases from top to bottom (He > Ne > Ar > Kr > Xe > Rn).
2. The noble gas...