Assertion : $$\mathrm{BO}_3^{-3}$$ and $$\mathrm{SO}_3^{-2}$$ are not isostructural.

Reason : In $$\mathrm{SO}_3^{2-}$$ sulphur has one lone pair of electron.

X and Y respectively are

The structure of $$\mathrm{IF}_7,$$ is

Assertion (A) Among the two $$\mathrm{O}-\mathrm{H}$$ bonds in $$\mathrm{H}_2 \mathrm{O}$$ molecule, the energy required to break the first $$\mathrm{O}-\mathrm{H}$$ bond and the other $$\mathrm{O}-\mathrm{H}$$ bond is same.

Reason (R) This is because the electronic environment around oxygen is the same even after breakage of one $$\mathrm{O}-\mathrm{H}$$ bond.