Respuesta :
The correct statement is: An atomic nucleus contains most of the atom’s mass.
All of the atom's neutrons and protons are in the nucleus, and the atom's electrons are outside the nucleus.
It would take more than 1,800 electrons to add up to the mass of one neutron or one proton.
But no atom has more than around 240 electrons, so we can see that almost all of the atom's mass is in the nucleus.