Concept:Ionic character depends on the electronegativity difference. The metal with the lowest ionization energy (most electropositive) forms the most ionic bond, while the one with the highest IE forms the least ionic (most covalent) bond.
Formula:$$ \text{Ionic Character} \propto \Delta\text{EN} $$
Solution:- Cesium (Cs) is at the bottom left of the periodic table. It is the most electropositive element, creating a massive electronegativity difference with Chlorine. CsCl has the greatest ionic character.
- Beryllium (Be) is at the top of Group 2. It has a very small size and high ionization energy, making it relatively electronegative for a metal. This gives \( \text{BeCl}_2 \) significant covalent character (least ionic).
Why other options are incorrect:- Option A, Option B, Option C: These options fail to pair the absolute extremes of electropositivity present in the list (Cs as highest, Be as lowest).
Quality & Fidelity Assurance:
Every question on BeambePrep is rigorously curated against the official PMDC syllabus with zero filler, zero out-of-syllabus content, and zero typos. When an authentic past paper originally contained a historical mistake or ambiguity from the examining board (such as UHS or NUMS), BeambePrep faithfully reflects the original paper while detailing the nuance and scientific consensus in the autopsy above.