An element with a molar mass 27g mol$^{-1}$ forms a cubic unit cell. Calculate the number of atoms present in a unit cell if the density of metal is 2.7g cm$^{-3}$.
$[a^3 \times N_A = 40$ cm$^3$ mol$^{-1}]$

A compound formed by elements A and B crystallizes in a cubic structure where A atoms are at the corner of the cube and B atoms are at the center of the cube. What is the formula of the compound?

Which of the following dopant is NOT used in Ge to obtain n-type semiconductor?

In a fcc arrangement of A and B atoms in which 'A' atoms are at the corners of the unit cell and 'B' atoms are at the face centers. One of the 'A' atoms is missing from one corner in unit cell. What is the simplest formula of a compound ?