Question

which best describes the effect of j. j. thomsons discovery?
the accepted model of the atom was changed.
the accepted model of the atom was supported.
cathode ray tubes were no longer used in experiments due to poor results.
cathode ray tubes became the only instrument of use in the study of atoms.

Explanation:

J. J. Thomson discovered the electron. Before his discovery, the atom was thought to be indivisible (like Dalton's solid - sphere model). His discovery led to the development of the plum - pudding model of the atom, which changed the previously accepted model of the atom (the solid - sphere model).

• The first option is incorrect because the model was changed, not just supported.
• The third option is wrong as cathode - ray tubes were still used in other experiments.
• The fourth option is also incorrect as cathode - ray tubes were not the only instrument used in atomic studies.

Answer:

The accepted model of the atom was changed.