Question

Which observation of Rutherford's a- particle scattering experiment showed that the mass and positive charge of the atom is concentrated?

Answer 1

The observation that only a few alpha rays deflected through large angle (180’) after collision with the gold foil led to the conclusion that positive charge is concentrated in a small area and is responsible for the mass of an atom .

Answer 2

a-particle are not reflecting back and it passing through the gold foil.only few a-particle are re bounding therefore mass and positive charge are in center