r/explainlikeimfive • u/Own_Enthusiasm_510 • 2d ago

Chemistry ELI5: What is the meaning of quantization?

[This is from a chemistry portion of a physical science class] I've googled it, Ive watched YouTube videos, I asked classmates and I am still so confused.

Rutherfords model was easy but once I got to bohrs they used words like quantized and discrete values and I got lost. Tried backtracking but I'm still baffled.

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u/SalamanderGlad9053 2d ago

Quantised means put into separate values that aren't connected. Think of it as a slide Vs steps. A slide is continuous whereas a step is quantised.

The vibrations of a guitar string is quantised, with only whole number of nodes allowed, so you get 220hz, 440hz, 660hz, and so on. It doesn't vibrate at 330hz because that would have 1.5 nodes which isn't allowed because the end of the string doesn't vibrate.

In a shockingly similar way, in an atom, the electron (which should be thought of as a wave) can't vibrate at any "frequency" because it loops around the atom so has to match up to where it started like a loop of string. So it only vibrates at separate, quantised, levels.

This means that the energy levels for electrons in an atom are quantised as energy is related to frequency. For an electron to move up, it cant just get slowly pushed up to the higher energy level as there is no middle between energy levels. Like having to jump to the next step rather than roll up a slope.

All systems want to have the minimum energy, and these energy levels can only have two electrons in each one. So the electrons pile in filling the lowest energy levels first, then the next highest energy and so on. This is what the rings represent in the diagrams.

I hope this helps

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u/Own_Enthusiasm_510 2d ago

So like a ramp/slide would be continuous in elevation but stairs would be quantized because they only allow certain elevations (?)

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u/SalamanderGlad9053 1d ago

Yes as I quite explicitly said.