J. j. thomson’s experiments provided evidence that an atom a. is the smallest particle of matter. b. contains negatively charged particles. c. has a negative charge. d. has a positive charge.

The correct answer is Option B.

Explanation:

The experiment given by J.J.Thomson was Cathode ray experiment.

In his experiment, he introduced an ionized gas in between the charged plates. The charged particles were released from cathode which cause the atoms of the gas to ionize. These particles were known as cathode rays. These rays are basically a stream of negatively charged particles known as electrons.

From this experiment, he concluded that all the atoms contain negatively charged particles known as electrons. Hence, the correct answer is Option B,

B. contains negatively charged particles I hope I've helped.