You are here
Choose the correct options and explain the reason for the correct and incorrect options in the context of Ernest Rutherford’s gold foil experiment: (i) The experiment clearly showed the existence of neutrons in the nucleus. (ii) The results disproved the plum pudding model and led to the idea of a nucleus at the centre of the atom. (iii) The large deflection of a few alpha particles indicated that most of the mass of the atom and positive charge are packed into a tiny centre. (iv) The way alpha particles were deflected showed that electrons move around the nucleus.
View Answer
Correct: (ii) and (iii).
- (i) Incorrect — the experiment revealed the nucleus , not neutrons (neutrons were found later by Chadwick).
- (ii) Correct — results disproved the plum pudding model and led to the idea of a central nucleus.
- (iii) Correct — large deflection of a few α-particles showed mass and positive charge are packed into a tiny centre.
- (iv) Incorrect — the deflection was due to the positive nucleus, not because it showed electrons moving around.
Statement (gold foil experiment)
Verdict & reason
(i)
The experiment clearly showed the existence of neutrons in the nucleus.
Incorrect
— it revealed the
nucleus
. The neutron was found later, by Chadwick in 1932.
(ii)
The results disproved the plum pudding model and led to the idea of a nucleus at the centre of the atom.
Correct
— a spread-out positive charge could never bounce an α-particle back.
(iii)
The large deflection of a few alpha particles indicated that most of the mass of the atom and positive charge are packed into a tiny centre.
Correct
— only a small, dense, heavy centre can turn α-particles through large angles.
(iv)
The way alpha particles were deflected showed that electrons move around the nucleus.
Incorrect
— the deflection was caused by the
positive nucleus
, not by the electrons.
