Determine if number is a prime number
To begin with, you don't need list_n at all: a decision that the number is composite can be made on the fly, as soon as some remainder becomes 0. If none of them were 0, you know that the number is prime:

    for n in range(2, x):
        if x % n == 0:
            return False
    return True


is effectively what your code is doing, but without the list, and without special case for 2.

That said, of course the algorithm could be greatly improved, but it is beyond the point of this exercise.