John knows that the atomic number of the element Chlorine, Cl, is 17. He also knows that one particular isotope of chlorine has a mass of 35. How many neutrons can be found in the nucleus of this isotope of chlorine?
Chlorine has 18 Neutrons and you can tell because its Atomic Number is 17 so 17 Protons now to have 35 so 35-17=18 because Neutrons are the other half of the weight of an element.
