The following compounds have been arranged in order of their increasing stabilities. Identify the correct order.
(I) `K_(2)CO_(3)` (II) `MgCO_(3)`
(III) `CaCO_(3)` (IV) `BeCO_(3)`

Options

A. `I lt II lt III lt IV`
B. `IV lt II lt III lt I`
C. `IV lt II lt I lt III`
D. `II lt IV lt III lt I`

Answer

3

Explanation

The thermal stabilites of carbonates increase down the group due to increase in metallic character `i.e.` electropositive character . Further bigger cation stabiliese bigger anion through crystal lattice energy effects.