By looking at your code, it seems like you're trying to let the user enter positive numbers until the user enters a negative number. To achieve this, you need to indent int(input("Enter a number, negative to stop")) inside the loop.
The second answer choice is correct.
The statement above is false; the motion of electrons can not be predicted precisely. Electrons move around the orbit shells at different energy levels in atoms. Previous research works had devised ways of measuring the angular velocity of electrons and means of tracking the movement of electrons in atoms but the movement of these electrons can not be predicted. They move in a random manner round the nucleus of an atom.<span />
