Question

1. describe the research, including instrumentation, which led to the conclusion that electrons are negatively charged particles found in all matter.

Explanation:

J.J. Thomson's cathode - ray tube experiment is relevant. Cathode - ray tubes were used. Cathode rays were deflected by electric and magnetic fields. The direction of deflection indicated negative charge. These rays were found in all cathode materials (matter).

Answer:

J.J. Thomson used cathode - ray tubes. He observed that cathode rays were deflected by electric and magnetic fields. The direction of deflection showed they were negatively charged. Since cathode rays could be produced from different cathode materials (different types of matter), it was concluded that electrons (the particles in cathode rays) are negatively charged particles found in all matter.