If both Statement - I and Statement - II are true, and Statement -II is the correct explanation of Statement - I. (b ) If both Statement - I and Statement - II are true but Statement - II is not the correct explanation of Statement - I.

If Statement - I is true but Statement - II is false.

If Statement - I is false but Statement - II is true. (i) STATEMENT-I : An important feature of Fluorite structures is that cations being large in size occupy FCC lattice points whereas anions occupy all the tetrahedral voids giving the formula unit: AB 2 (A : cation, B : anion ). STATEMENT-II: There are 6 cations and 12 anions per FCC unit cell of the fluorite structure (ii) STATEMENT- I : In NaCl crystal each Na + ion is touching 6 Cl – ions but these Cl – ions do not touch each other. STATEMENT-II : The radius ratio is greater than 0.414, required for exact fitting. (iii) STATEMENT-I: ZnO beomes yellow when it is heated. STATEMENT-II: NaCl becomes yellow when heated in the presence of Na vapours due to anion vacancy .