Among the following,the incorrect statement is:

Calculate the number of atoms present in $1.58 \ g$ of a metal that forms a $bcc$ structure,given that $\varrho \times a^3 = 1.58 \times 10^{-22} \ g$.

$A$ mixture of $KCl$ and $KF$ is added to sodium chloride.

Silver has an atomic radius of $144 \ pm$ and the density of silver is $10.6 \ g \ cm^{-3}$. Based on this information, identify the correct statement.

The cubic unit cell structure of a compound containing cation $M$ and anion $X$ is shown below. When compared to the anion,the cation has a smaller ionic radius. Choose the correct statement$(s)$:
$(A)$ The empirical formula of the compound is $MX$.
$(B)$ The cation $M$ and anion $X$ have different coordination geometries.
$(C)$ The ratio of $M-X$ bond length to the cubic unit cell edge length is $0.866$.
$(D)$ The ratio of the ionic radii of cation $M$ to anion $X$ is $0.414$.

In the given cooling curve,what is the crystallization temperature in $K$?