Zero is a Rational Number

Rational number is define as a rational number is a number that can be written in the form p/q, where p and q are integers and q is not equal to 0.

We know that the integer 0 is written in any of the form such as 0/1, 0/3, 0/5, o9, where 
denominator q is a non zero integer.  

Examples of the rational numbers are 2/3, 4/7, -3/2, 7, -5, 0 etc. 

Hence, we conclude that 0 is a rational number.

Therefore we can say, zero is a rational number.