An element M crystallises in a body centred cubic unit cell with a cell edge of $$300 \,\mathrm{pm}$$. The density of the element is $$6.0 \mathrm{~g} \mathrm{~cm}^{-3}$$. The number of atoms present in $$180 \mathrm{~g}$$ of the element is ____________ $$\times 10^{23}$$. (Nearest integer)

Metal deficiency defect is shown by Fe_0.93O. In the crystal, some Fe²⁺ cations are missing and loss of positive charge is compensated by the presence of Fe³⁺ ions. The percentage of Fe²⁺ ions in the Fe_0.93O crystals is __________. (Nearest integer)

In a solid AB, A atoms are in ccp arrangement and B atoms occupy all the octahedral sites. If two atoms from the opposite faces are removed, then the resultant stoichiometry of the compound is A_xB_y. The value of x is ____________. [nearest integer]

The distance between Na⁺ and Cl^$$-$$ ions in solid NaCl of density 43.1 g cm^$$-$$3 is _______________ $$\times$$ 10^$$-$$10 m. (Nearest Integer)

(Given : N_A = 6.02 $$\times$$ 10²³ mol^$$-$$1)