In a face-centered cubic unit cell,what fraction of an atom at the corner is shared by the unit cell?

In a face-centered cubic arrangement of $A$ and $B$ atoms,$A$ atoms are at the corners of the unit cell and $B$ atoms are at the face centers. If one of the $B$ atoms is missing from one of the faces in the unit cell,the simplest formula of the compound is:

$A$ compound is formed by elements $A$ and $B$. Element $A$ occupies the corners of the cube,and element $B$ occupies the face centers. What is the formula of the compound?

What is the number of atoms per unit cell in a face-centered cubic $(FCC)$ crystal lattice?

Copper crystallizes in $f.c.c.$ with a unit cell length of $361 \ pm$. What is the radius of copper atom? (in $pm$)

$Pt$ has an $FCC$ structure with an edge length of unit cell $392 \text{ pm}$. What is the radius of $Pt$ (in $\text{ pm}$)?