What is the type of hole occupied if the limiting value of $\frac{r+}{r-}$ is in the range of $0.225$ to $0.414$?

$A$ compound is formed by elements $X$, $Y$, and $Z$. Atoms of $Z$ (anions) make $FCC$ lattice. Atoms of $X$ (cations) occupy all the octahedral voids. Atoms of $Y$ (cations) occupy $\frac{1}{3}$ rd of the tetrahedral voids. The formula of the compound is:

$A$ metal having atomic mass $60.23 \ g/mol$ crystallises in $ABCABC$ close packing. Calculate the density of a single metal atom if the edge length of the unit cell is $10 \ \mathring{A}$. [Given: $N_A = 6.023 \times 10^{23}$]

In a compound $XY$,the atoms of element $Y$ form a $ccp$ structure,while the atoms of element $X$ occupy $2/3$ of the tetrahedral voids. The molecular formula of the compound will be ..........

Explain the Hexagonal Close Packing $(hcp)$ and Cubic Close Packing $(ccp)$ or Face-Centered Cubic $(fcc)$ structures.

In a crystalline solid,anion $B$ are arranged in $ccp$ lattice and cation $A$ occupy $50\%$ of the octahedral voids and $50\%$ of tetrahedral voids. What will be the formula of the crystalline solid?