関連ワード:  which is heavier electron or proton    which is heavier electron or proton or neutron    which is heavy electron or proton    which is heaviest electron proton or neutron    which one is more heavier electron or proton    which is heavier among electron proton and neutron    which is heaviest among electron proton and neutron    which is heavier mass of electron or mass of proton    which particle is heavier proton or electron    which is more heavier electron or proton