According to Rutherford nuclear model of atom, very few particles are bounced back, this is because: (Analyze/evaluate)

The correct answer is: Mass is concentrated at the center of nucleus

Rutherford's α-particle scattering experiment, most of the α-particles were deflected by nearly 1800. Reason: The positive charge of the atom is spread throughout the atom that repelled and deflected the positively charged α-particles.This is due to the fact that like charges repel each other. As the positively charged alpha particle would fly through the foil it would come in proximity with the positively charge nucleus of the atom. This in turn either deflected the particle or adjusted its path.