In a face-centered cubic $(FCC)$ unit cell,how many unit cells share an atom located at the face center?

Which of the following structures is not correctly matched?

If the distance between $Na^{+}$ and $Cl^{-}$ ions in $NaCl$ crystal is $a \, pm$, what is the length of the cell edge?

$A$ compound contains $Ca, Ti$ and $O$ elements. If $Ca^{2+}$ ions are at the corners of the cube,$Ti$ ions are at the body center,and $O^{2-}$ ions are at the face centers,then the molecular formula of the compound and the oxidation state of $Ti$ are respectively ........

In a $BCC$ lattice containing $X$ and $Y$ type of atoms,$X$ type of atoms are present at the corners and $Y$ type of atoms are present at the body center. In its unit cell,if three atoms are missing from the corners,the formula of the compound is:

In a body-centered cubic $(BCC)$ unit cell,the atom at the body center is shared by how many unit cells?