Which among the following crystal lattices occupies all of the cubic holes by cations?

The number of nearest neighbours and next nearest neighbours of an $Na^{+}$ ion in a crystal of $NaCl$ are respectively

Which of the following is a $1:2$ type compound?

What is the coordination number of a particle in a simple cubic structure?

The coordination number of $Ba^{2+}$ ion in Barium fluoride $(BaF_2)$ is $8$. What must be the coordination number of fluoride ion $(F^{-})$?

$A$ solid has a structure in which $W$ atoms are located at the corners of a cubic lattice,$O$ atoms are at the center of the edges,and $Na$ atoms are at the center of the cube. The formula for the compound is: