Chemistry

Question Analysis
This question involves determining the number of successive ionization energies needed to identify an element’s group. The main focus is on using energy jumps to distinguish valence from core electrons.

Key Concept Explanation
Group 2 elements have 2 valence electrons. A large jump in ionization energy occurs after removing all valence electrons (i.e., between the 2nd and 3rd ionization energies). To confirm this jump, at least 3 ionization energy values are required.

Step-by-Step Solution
1. Group 2 elements have 2 valence electrons.
2. A single ionization energy (A) cannot indicate valence electron count.
3. Two ionization energies (B) can show a gradual increase but no jump to confirm core electron removal.
4. Three ionization energies (C) allow comparison of the 1s...