Question

scientists have changed the model of the atom as they have gathered new evidence. one of the atomic models is shown below. what experimental evidence led scientists to change from the previous model to this one? a few of the positive particles aimed at a gold foil seemed to bounce back. the colors of light emitted from heated atoms had very specific energies. experiments with water vapor showed that elements combine in specific proportions. cathode rays were bent in the same way whenever a magnet was brought near them.

Explanation:

• Option A: Rutherford's gold - foil experiment (where a few positive particles bounced back) led to the nuclear model (which this model resembles with a central nucleus).
• Option B: The specific energies of light emitted from heated atoms is related to the Bohr model (energy levels of electrons), but the given model is more about the nuclear structure.
• Option C: Experiments with water vapor (definite proportions) are related to the law of definite proportions (not atomic model change).
• Option D: Cathode - ray bending (by a magnet) led to the discovery of electrons (Thomson's plum - pudding model, not the nuclear model).

Answer:

A. A few of the positive particles aimed at a gold foil seemed to bounce back.