Answer: The iodide ion is large and most easily polarised by the small Li+.
- A Lithium iodide has the highest lattice enthalpy of all the halides
- B The iodide ion has the highest charge
- C The iodide ion is large and most easily polarised by the small Li+
- D The iodide ion is the least polarisable anion
Correct answer: C. The iodide ion is large and most easily polarised by the small Li+
Explanation: The large, highly polarisable I- ion is distorted most by the small high-charge-density Li+, giving the greatest covalent character among LiF, LiCl, LiBr and LiI.
Each s-block metal ion emits a characteristic flame colour because heating excites electrons to higher energy levels; light is emitted as they fall back, with the colour determined by the specific energy gap.
Concept context
Group 1 (alkali metals) and Group 2 (alkaline earth metals). Learn their reactions with water and air, important compounds like NaOH, Na₂CO₃, and CaCO₃, and anomalous behaviour of lithium and beryllium.