yego.me
💡 Stop wasting time. Read Youtube instead of watch. Download Chrome Extension

Thomson's Plum Pudding Model of the Atom


2m read
·Nov 10, 2024

So the word atom means uncuttable, so the Greeks were thinking of it as a tiny hard sphere.

Phil: That's right.

Derek: And even up until the eighteen hundreds, that was the idea of an atom, the smallest piece of matter, a tiny hard sphere. But then we find out that that's not quite right, not quite. There were experiments in the eighteen hundreds that discovered the electron. JJ Thomson's experiments really worked out the electron was smaller than an atom, about 1000 times smaller than a hydrogen atom, and it was in all atoms.

Phil: That's right, not just hydrogen.

Derek: Whatever material he did his experiments on, he found there were electrons in them. There are electrons in all atoms. So I guess when you find something smaller than an atom, you need to propose a new model for the atom that actually has something smaller in it, some substructure.

Phil: That's right. So something like this. This is our model of the atom.

Phil: This is our model of the atom - in his day, it was known as the plum pudding model, but uh... here we have cherry tart.

Phil: Cherry tart, ok. So the idea being that we have an overall atom, usually pictured as spherical rather than 2D, but uh... but imbedded within it – and this is the important part – there are negative electrons represented by cherries, and they can come out. The overall atom is neutral, so that means that pudding part must be positive.

Derek: Now how would you get one of these electrons out of our pudding here? So electrons are negatively charged, so we'll need to put something very positive, which attracts electrons – a high voltage.

Derek: And that would have the effect of, say, like plucking a cherry out of the pudding.

Phil: That's pretty much it, yeah. You could do it kind of like that, so we're simulating what it would be like to put a positive charge up here.

Phil: That's right, that's right.

Derek: Pulling the electrons out of the atom, that's quite delicious.

Phil: Yeah! Well, that is the most delicious model of the atom, I've gotta say. So shall we uh, split the atom? Why don't you go ahead?

Phil: You want me to do it?

Derek: Yes! Who knows what could happen; a whole bunch of energy could be released.

Phil: Yeah, one, two, three...

More Articles

View All
Passing Obama’s Stimulus Bill | Obama: The Price of Hope
NARRATOR: Obama needs just two Republican senators to defy their party. He turns to the veteran leader of the Senate Democrats. None of the Republicans who wanted to do something to help wanted to be the 60th vote. So I had to get 61 votes on everything. …
The Fear of Death
[Music] Foreign death can only be interpreted by people who are alive. Yet since no one who is alive can simultaneously experience what it’s like to be dead, who then does death actually concern? This logic is oddly reassuring. Even so, if my doctor were …
Comparing P-value from t statistic to significance level | AP Statistics | Khan Academy
Jude was curious if the automated machine at his restaurant was filling drinks with the proper amount. He filled a sample of 20 drinks to test his null hypothesis, which is the actual population mean for how much drink there was in the drinks per drink is…
Dilutions | Chemistry | Khan Academy
Your friends are coming over, so you decide to make some Kool-Aid for them. You happen to have a very concentrated Kool-Aid solution. This is the molarity of the amount of sugar that you have: 4 moles of sugar per liter, which is apparently a very sweet s…
How To Make Friends
Friends make life good. They provide the scaffolding that makes it not just bearable, but fun. They give us a sense of meaning and purpose and are a source of security, self-esteem, and happiness. Almost nothing predicts how happy you will be as how conne…
Quotients that are multiples of 10 | Math | 4th grade | Khan Academy
Let’s solve 240 divided by three. To solve this, we could take this large three-digit number and divide it by a one-digit number, or we could take what we know about tens and zeros and try to break this up into numbers that might be easier for us to work …