3. Which particles of an atom have the greatest mass?
A. Proton and electron
B. Proton, neutron, and electron have the same mass
C. Electron and Neutron
D. Proton and Neutron

3 Which particles of an atom have the greatest mass A Proton and electron B Proton neutron and electron have the same mass C Electron and Neutron D Proton and N class=