Question

Which atomic models in task 1 are not supported by Thomson’s experimental evidence? For each of these models, explain the experimental results that the model would predict.

Answer 1

Answer:

To test the properties of the particles, Thomson placed two oppositely-charged electric plates around the cathode ray. The cathode ray was deflected away from the negatively-charged electric plate and towards the positively-charged plate. This indicated that the cathode ray was composed of negatively-charged particles.

Thomson also placed two magnets on either side of the tube, and observed that this magnetic field also deflected the cathode ray. The results of these experiments helped Thomson determine the mass-to-charge ratio of the cathode ray particles, which led to a fascinating discovery−-−minusthe mass of each particle was much, much smaller than that of any known atom. Thomson repeated his experiments using different metals as electrode materials, and found that the properties of the cathode ray remained constant no matter what cathode material they originated from. From this evidence, Thomson made the following conclusions:

The cathode ray is composed of negatively-charged particles.

The particles must exist as part of the atom, since the mass of each particle is only ~1/2000 the mass of a hydrogen atom.

These subatomic particles can be found within atoms of all elements.

While controversial at first, Thomson's discoveries were gradually accepted by scientists. Eventually, his cathode ray particles were given a more familiar name: electrons. The discovery of the electron disproved the part of Dalton's atomic theory that assumed atoms were indivisible. In order to account for the existence of the electrons, an entirely new atomic model was needed.

Explanation:

Answer 2

Answer:

Dalton's atomic model and Rutherford model

Explanation:

There were differences in the models:

Thompson's experiment showed that atoms contained tiny negatively charged particles called electrons.

On the other hand, Rutherford gold experiment led to the conclusion that the atom is a empty space with tiny, dense and positively charged nucleus.

Dalton thought that atoms were the smallest units of matter that could not be broken down further. This assumption continued to hold until it was later discovered that the atom was composed of subatomic particles.