Why can samples of an element have same atomic number but different atomic masses?

This is because the atomic mass of an element is the sum of protons and neutrons. While the proton number is specific for an element, the neutron number can vary for different isotopes of the element. Therefore an element with a higher number of neutrons will have a higher atomic mass number.

FB

Related Chemistry GCSE answers

All answers ▸

What is the empirical formula of a compound with the following composition by mass, 48.0g C, 4.0g H and 48.0g O?


Why does the reactivity of group 1 elements increase as you go down the group?


Why is this reaction an Endothermic reaction?


How does the reactivity of group 7 elements (the halogens) change down the group and why? (A Level)