Answer:
zero(0)
Explanation:
The additive identity of a set of number is a number such that the its sum with any of the numbers in the set would give a result that is equal to the number in that set.
In other words, say for example the set of numbers is rational, the additive identity of rational numbers is 0. This is because, given any rational number say x, adding zero to the number x gives the same number x. i.e
x + 0 = x
If x is say 2, then we have;
2 + 0 = 2
Since adding zero to rational numbers gives has no effect on the numbers, then zero (0) is the additive identity of rational numbers.