THOMPSON THE MINUS
- MHK
- May 29, 2020
- 3 min read
AUTHOR: MAHIR KAYA
DATE: MAY 29/ 2020
In our latest posts about atoms, we saw that scientists think of atoms as structural spheres but atoms are actually much more than spheres. They have an internal structure, internal particles, what we call subatomic particles. There are three main subatomic particles of atoms, electrons, neutrons and protons. And today’s lucky particles to be discovered by our next scientist, J..J Thomson , are electrons.
First of all, who is this J.J. Thompson? He was born in England on 18 December 1856. He was a physicist and credited for the discovery of electrons. He was given a Nobel Prize for his work on electricity conduction in gases. His death was on 30 August 1940.
Now that we have a background about who was J.J. Thomson, we can look into his work and how did he contribute to the long process of discovery of atoms. We already said that he was credited for the discovery of the electron but how did he do it? How did he discover the negative particles? The answer for those questions is that he used cathode ray tube technology. But how does tube thingy work? Well, it can be explained in few steps:
1) First of all, there is an empty tube which air was sucked out from. There are cathode and anode sides in the tube.
2) Then, an electric charge passes through the tube which travels from cathode to anode.
3) To see where the charge goes, we put a fluorescent screen on the anode side of the screen. There will be a dot where the charge hits the fluorescent screen.
4) This beam of charge would go straight if not interfered with. But we would like to interfere with it. So we would put a negative and a positive coil.
5) After those interference with the charge, we would see the charge would deflect away from the negative coil and would move through the positive coil.
6) As a result, since the charge is deflecting away from the negative coil, Thompson stated that the charge was negative.
There is an example of the cathode ray tube below:
This tube technology was used in nearly all computer monitors and televisions until the use of plasma and LCD.
But Thompson did not stop just by finding the electron, he named this particle "corpuscles". Then went further and predicted the mass of it. He found out that the mass of this charge was 1000 times lighter than the mass of the hydrogen atom. That was when he decided that then this charge must've been inside an atom.
Now that we understood how he discovered the electron, we can look into his atomic model. We can summarize his key points with the following four articles:
1) Thompson said that each atom was a sphere filled with a "positive" fluid.
2) Corpuscles ( electrons) are negatively charged particles which was suspended in this fluid.
3) Thompson did not predict the movement of the electrons.
4) Because of the design, this atomic model is known as plum pudding model.
Now, since this post was longer than the others, I am not going to close with a fancy conclusion paragraph. Just you should be aware that you can comment and ask me questions if you have some anytime .
SOURCES:
WIKIPEDIA
THOMPSON PHOTO SOURCE:
https://images.fineartamerica.com/images-medium-large/jj-thomson-english-physicist-photo-researchers.jpg
CATHODE RAY TUBE GIF SOURCE:
THOMPSON ATOM MODEL IMAGE SOURCE:
https://www.universetoday.com/wp-content/uploads/2009/08/plum-pudding-model.jpg
https://image.shutterstock.com/image-vector/thomsons-model-260nw-154448771.jpg
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