Question

Which of the following experimental observations proved that the idea of matter and mass being evenly distributed in an atom was flawed?
A. Less than 1% of the alpha particles went un-deflected through the gold foil.
B. Less than 1% of the alpha particles were deflected by angles greater than 90°.
C. The beam from the negative electrode was deflected by electrically charged rods.
D. The beam from the negative electrode cast a shadow on the positive electrode.

Answer 1

A. Less than 1% of the alpha particles went un-deflected through the gold foil.

Answer 2

Answer:

B. Less than 1% of the alpha particles were deflected by angles greater than 90°.

Explanation:

In Rutherford’s gold foil experiment most of the alpha particles pass undeflected which proved that most of the atom is empty. Less than 1% of the alpha particles were deflected by angles greater than 90°. This proved that the entire mass of the atom is confined to a small space which is highly dense.