# Which has more mass - the nucleus or electron cloud?

If you look at the masses of fundamental particles, the mass of the proton and the neutron dwarf that of the electron. Mass of proton/neutron, $1.67 \times {10}^{- 27} \cdot k g$; mass of electron, $9.11 \times {10}^{- 31} \cdot k g$; so approx. 4 orders of magnitude difference.