Yes. By definition, integers consist of all positive whole numbers (i.e., 1, 2, 3, and so on), their opposites (i.e., -1, -2, -3, and so on), and zero. The first group are the positive integers, the second are the negative ones, while 0 is neither positive nor negative.

Yes. By definition, an integer is a number that we can express without fractional expressions. For instance, the number 2 is clearly an integer, but we can also write it as ⁴/2, which is a fraction but a reducible one.

Yes. By definition, integers consist of all positive whole numbers (i.e., 1, 2, 3, and so on), their opposites (i.e., -1, -2, -3, and so on), and zero. The second group clearly involves negative numbers.