If the radius ratio limit is $0.414 - 0.732$,what will be the coordination number?

In an alloy of metals $M$ and $N$,$N$ atoms form a $bcc$ structure,while $M$ atoms occupy the center of each face. If the cube is cut such that all atoms along one body diagonal are removed,the formula of the resulting solid will be ...........

Diamond has a three-dimensional structure of $C$ atoms formed by covalent bonds. The structure of diamond has a face-centered cubic $(FCC)$ lattice where $50\,\%$ of the tetrahedral voids are also occupied by carbon atoms. The number of carbon atoms present per unit cell of diamond is $......$

The arrangement of $X^{-}$ ions around $A^{+}$ ion in solid $AX$ is given in the figure. If the radius of $X^{-}$ is $250 \ pm$, the radius of $A^{+}$ is: (in $pm$)

The space lattice of $CaF_2$ is:

Which of the following is correct for the crystal lattices mentioned below?