Which of the following experimental observations proved that Dalton's postulate about the indivisibility of the atom was flawed?
A. Cathode rays inside the tube deflected towards a negatively charged rod.
B. Cathode rays inside the tube deflected towards a positively charged rod.
C. A few alpha particles bounced back during the scattering experiment.
D. All alpha particles went straight during the scattering experiment.

B. Cathode rays inside the tube deflected towards a positively charged rod, because the cathode ray is composed of negatively-charged particles (negatively charged subatomic particles or electrons).

C. A few alpha particles bounced back during the scattering experiment. Rutherford theorized that atoms have their charge concentrated in a very small nucleus.

This was famous Rutherford's Gold Foil Experiment: he bombarded thin foil of gold with positive alpha particles (helium atom particles, consist of two protons and two neutrons).

Rutherford observed the deflection of alpha particles on the photographic film and notice that most of alpha particles passed straight through foil.

sarajevo sarajevo · Answer 2 · 2019-04-13T08:45:32+02:00

sarajevo sarajevo

13-04-2019

Answer:

C. A few alpha particles bounced back during the scattering experiment.

Explanation:

Rutherford's gold foil experiment proved that the center of the atom is dense which caused some of the alpha particles to bounce back. This proved that most of the mass of the atom is located at the center, however, the rest of the atom is empty. It also showed that the center of the atom stores all the positive charges.

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