Question

What is a lattice? What is a unit cell? Describe a simple cubic unit cell. How many net atoms are contained in a simple cubic unit cell? How is the radius of the atom related to the cube edge length for a simple cubic unit cell? Answer the same questions for the body-centered cubic unit cell and for the face-centered unit cell.

Answer 1

Lattice: a regular geometrical arrangement of points or objects over an area or in space
Unit cell: a repeating unit formed by the vectors spanning points of a lattice.
Cubic unit cell: the smallest repeating unit when all angles are 90 degrees and all lengths are equal
Relation between radius atom and cube edge: the edge length of this cell is equal to two atomic radii or one atomic diameter