An element $X$ (At. wt. $= 80 \ g/mol$) has an $fcc$ structure. Calculate the number of unit cells in $8 \ g$ of $X$.

Elements $A$ and $B$ have $fcc$ and $bcc$ structures respectively with a unit cell edge length of $3 \mathring{A}$ for both elements. The number of atoms in $210 \ g$ of $A$ is equal to the number of atoms in $594 \ g$ of $B$. If the density of $A$ is $7 \ g \ cm^{-3}$,what is the density of $B$ (in $g \ cm^{-3}$)?

What is the volume of one particle in $BCC$ structure if '$a$' is edge length?

$A$ metal crystallizes in two phases,one as $fcc$ and another as $bcc$ with unit cell edge lengths of $3.5 \mathring{A}$ and $3.0 \mathring{A}$,respectively. The ratio of density of $fcc$ and $bcc$ phases approximately is

If $M$ is the atomic mass of an element and $a$ is the edge length of the unit cell,then the formula to calculate the density $\rho$ is:

Sodium metal crystallises in a body-centred cubic $(BCC)$ lattice with an edge length of $x \ \mathring{A}$. If the radius of the sodium atom is $1.86 \ \mathring{A}$, the value of $x$ is: