(a) A number which has only two factors is called a Prime number

Explanation: A number which has only two whole number factors is called a prime number. It has only two whole number factors i.e. on the number itself and other     Example: 2 is a prime number.

(b) A number which has more than two factors is called a Composite number

Explanation: A number which has more than two factors is called a composite number.

Example: 4 is a prime number.

(c) 1 is neither prime nor composite 

Explanation: 1 is neither prime nor composite number. Because 1 has no other whole number factor other than itself. So, it's not prime and therefore not composite as well.

(d) The smallest prime number is 2

Explanation: The smallest prime number is 2 because, it has only two whole number factors, one the number itself and other 1.

(e) The smallest composite number is 4

Explanation: The smallest composite number is 4 because, it has only three whole number factors i.e. 1, 2 and 4.

(f) The smallest even number is 2

Explanation: The smallest even number is 2. Because an integer divisible by 2 is an even number.