J.J Thompson discovered that cathode rays are:
A)emitted from the nucleus of an atom
b)a stream of charged atoms
c)a result of nuclear reactions
d)composed of tiny, negativley charged particles
I believe it is D.
I found this on a website:
"JJ Thompson discovered the electron by experiments that showed cathode rays had momentum. For an object to have momentum it must have a mass, so the cathode ‘rays’ must actually be a stream of particles, electrons."
Yes, the answer is (d)
The correct answer to the question "J.J. Thompson discovered that cathode rays are:" is (d) composed of tiny, negatively charged particles.
To understand how J.J. Thompson came to this conclusion, we need to explore his famous experiment, known as the Cathode Ray Tube experiment. Here's a step-by-step explanation of the experiment and how it led to his discovery:
1. Thompson set up a Cathode Ray Tube (CRT), which consists of a sealed glass tube containing a cathode (negatively charged electrode) at one end and an anode (positively charged electrode) at the other end.
2. He applied a high voltage across the electrodes, creating an electric field within the tube.
3. Once the electric field was applied, he observed that a ray of light, known as the cathode ray, originated from the cathode and moved towards the anode.
4. He noticed that the cathode ray could cast a shadow on a fluorescent screen placed inside the tube, indicating that it was a stream of particles.
5. One of Thompson's crucial findings was that the cathode rays could be deflected by both magnetic fields and electric fields.
6. By manipulating the magnetic and electric fields, Thompson was able to measure the ratio of the charge (e) to the mass (m) of the particles in the cathode ray.
7. By carefully studying these deflection experiments, Thompson concluded that the cathode rays were made up of tiny, negatively charged particles, later known as electrons.
Therefore, Thompson's discovery from the Cathode Ray Tube experiment was that cathode rays consist of tiny, negatively charged particles, which we now recognize as electrons.