Yes zero is a rational number. A rational number is any number that can be written as a ratio of two integers. Every integer is a rational number, since each integer n can be written in the form n/1.
We know that the integer 0 can be written in any one of the following forms.
For example, 0/1, 0/-1, 0/2, 0/-2, 0/3, 0/-3, 0/4, 0/-4 and so on …..
In other words, 0 = 0/b, where b is any non-zero integer
Thus, 0 can be written as, where a/b = 0, where a = 0 and b is any non-zero integer.
Hence, 0 is a rational number.