Due to vacancy defects,the density of a solid substance .............

Select the incorrect statement.

Calcium crystallizes in a face-centred cubic $(FCC)$ lattice with an edge length of $556 \ pm$. Calculate the density if:
$(i)$ There is $0.1 \%$ Schottky defect.
$(ii)$ There is $0.1 \%$ Frenkel defect.

Which of the following does not change the density of $SiC$ solid?

For $NaCl$,the number of Schottky pairs per $cm^3$ at room temperature is

The formula of a metal oxide is $M_{0.96} O_1$. The fractions of metal that exist as $M^{3+}$ and $M^{2+}$ ions in that oxide are respectively