What is the number of atoms per unit cell for each metal?

In the question, the number of atoms per unit cell is required for:

A) Polonium (Po)

In polonium, the structure is simple cubic, meaning there are 8 corner atoms, which add up to one atom per unit cell.

B) Manganese (Mn)

The structure of the Mn can be considered to be a body centered cubic (BCC) and the number of atoms for this is 8 corner atoms and 1 central atoms, making a total of 2 atoms per unit cell.

C) Silver (Ag)

Silver has a face centered cubic (FCC) unit cell structure, where there are 8 corner atoms and 6 atoms on the faces, so there are a total of 4 atoms per unit cell.