Question

Particles which were deflected backward in Rutherford's experiment were hit upon by ________.

• A. nucleus
• B. empty space
• C. electrons
• D. ions

Answer 1

The correct option is A nucleus

In Rutherford's experiment, very few α-particles were deflected back, that is only a few α-particles had nearly ${180}^0$ angle of deflection.
He proposed that the mass of the atom and the positive charge was concentrated at a small volume in an atom.
He named this small volume "the nucleus".
So, it was this positively charge nucleus that made the α-particles to bounce back.