If we perform ruther ford's scattering experiment we will find that some of the alpha particles bounce back the same path..this proves the existence of nucleus
in an experiment conducted by Rutherford,,,,,,,,,,,,,,
# most particles passed through the gold foil without any  deflection.
# small particles were deflected through small  angles.
# a very small fraction of particles were deflected through large angles or bounced back.
he says that since a very small fraction of particles deflecting through large angles or bouncing back indicated that the positive charges must be concentrated in a dense mass at the centre of the atom . he named this dense mass the nucleus. he proposed that all the protons must be concentrated in the nucleus.
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