Chemistry

Question Analysis
This question involves identifying the element with the highest first ionization energy overall. The main focus is on applying the group trend to noble gases and recognizing the extreme value for helium.

Key Concept Explanation
Noble gases have the highest ionization energies in their periods.
Down Group 18, ionization energy decreases due to increased atomic radius and shielding.
Helium (the topmost noble gas) has the smallest atomic radius and no inner electron shielding, making it the element with the highest first ionization energy.

Step-by-Step Solution
1. Compare helium (He) and neon (Ne): both are noble gases.
2. He is in Period 1 (to...