In the simple cubic unit cell, the centers of     identical particles define the     of a cube. the particles do touch along the cube's     but do not touch along the cube's     or through the center. there is/are     particle per unit cell and the coordination number is     .

In the simple cubic unit cell, the centers of eight identical particles identical particles define the corners of a cube. The particles do touch along the cube's edges,  but do not touch along the cube's diagonally or through the center. There is/are eight particle (one atom) per unit cell and the coordination number is six.
There is three types of cubic cell:
1) simple cubic unit cell.
2) body-centered cubic unit cell.
3) face-centered cubic-unit cell.
The simple cubic unit cell is the simplest repeating unit in a simple cubic structure, the edge of a unit cell always connects equivalent points 

Where's the pictures ?