What evidence from J. J. Thomson's experiments with the cathode ray led to the plum pudding model of the atom? A. The beam was attracted to a positive charge and repelled by a negative charge, showing that atoms contain small, negatively charged particles. B. The beam was attracted to a negative charge and repelled by a positive charge, showing that atoms contain small, positively charged particles. C. The beam was positively charged and had significant mass, showing that atoms have a positive, dense nucleus. D. The beam was neutral and had significant mass, showing that atoms contain neutral particles in the nucleus.

A. The beam was attracted to a positive charge and repelled by a negative charge, showing that the atoms contain small, negatively charged particles.

Answer. Statement A is correct statement.

Explanation:

Thomson in his experiment named Cathode Ray Experiment he found that many of the metals release cathode rays which are negatively charged due to the presence of negatively charged subatomic particles that is electrons.

Rays were allowed to pass between the two oppositely charged plates, he observed that the rays were attracted towards positively charged plates and got repelled by the negatively charged plate.

From which he concluded that the atoms contain small, negatively charged particles known as electrons.

So from the statements provided in the question only statement A tells us about the the observation made by the Thomson in his cathode ray experiment where as other three statements are not in agreement with those observations.