Brenda,

For an integer to be prime it must be greater than 1, and the only integers that divide into it exactly are 1 and itself such as 3 and 13, etc. 0 is less than 1 so can't be prime. Composite integers are those that are the products of primes such as 6 = 2x3. 0 cannot be expressed as a product of primes because such products are non-zero.

Penny