I was watching a video about quarks and they said that they made an experiment where they fired electrons into protons and saw how they bounced.
All this makes my head hurt like.. how do they do that? How to they see what happens when the electrons are fired? How so they see where they bounce?
You can’t observe all this with microscopes right? So how does it all work?
In: Chemistry
First you need to create a beam of electrons. Basically you can do this by just heating up a piece of metal and use a high electrical voltage (multiple kilovolt or higher on it), to accelerate them.
Then you direct this beam onto a target. This target is what you want to investigate. The electrons of your beam will interact somehow with your target and it might change the direction of electrons in your beam, it might change the energy of your electrons, create new electrons, create light, etc.
These changes you can measure with specialized detectors. You cannot “see” electrons with them directly, but basically you get an electrical signal which is somewhat related to the quantities you can measure.
Or if you have high enough energies you can visualize the electrons by directing it on a phosphorous screen, where the electrons create light, allowing you to see in which directions the electrons move.
You can use all of this information, to get information about crystal structure of a material, what elements it contain, what electronic properties it has and more. You can even use an electron beam to make high resolution pictures of the samples (which is then called electron microscopy).
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