In the closest packed structure of a metallic lattice,the number of nearest neighbours of a metallic atom is

The structure of $Na_2O$ crystal is

The crystal structure of $AB$ is of $NaCl$ type. If the radius of the $A^+$ ion is $x \ pm$ and the radius of the $B^-$ ion is $y \ pm$, then the edge length of the unit cell will be ..........

$A$ compound made of elements $A$ and $B$ forms an $fcc$ structure. Atoms of $A$ are at the corners and atoms of $B$ are present at the centres of the faces of the cube. What is the formula of the compound?

$A$ solid $AB$ has a $NaCl$ structure. $B$ atoms are at the corners and all face-centered positions of the unit cell,while $A$ atoms occupy all the $O.H.V.$ (Octahedral Voids). If all the atoms from the face-centered positions along one axis are removed,what will be the resulting stoichiometry of the solid?

$A$ crystal is formed by two elements $X$ and $Y$ in a cubic structure. $X$ atoms are at the corners of a cube,while $Y$ atoms are at the face centers. The formula of the compound will be: