Kind: captions
Language: en
So the word atom means uncutable.
That's right.
So the Greeks were thinking of it as a
tiny hard sphere.
That's right.
And even up into the 1800s, that was the
idea of an atom. The smallest piece of
matter, tiny hard sphere.
Yep. Yep.
But then we find out that that's not
quite right.
Not quite. There were experiments in the
1800s that discovered the electron. JJ
Thompson's experiments um really worked
out the electron was smaller than an
atom. Smaller than the about a thousand
times smaller than the hydrogen atom
and it was in all atoms.
That's right. Not just hydrogen.
Whatever material he did his experiments
on, he found their electrons in them.
There are electrons in in all atoms. So
I guess when you find something that's
smaller than an atom, you need to
propose a new model for the atom that
actually has something smaller in it.
Some substructure.
That's right. So you know something like
this. This is our model of the atom.
This is our model of in his day it was
known as the plum pudding model. But uh
here we have
cherry tart.
Cherry tart. Okay. So but the idea being
that we have an overall atom usually
pictured as spherical rather than 2D.
But um but embedded within it 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 the pudding part
must be positive.
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
and that would have the effect of say
like plucking a [snorts] cherry out of
the pudding.
That's [laughter]
pretty much it. Yep. I you could do it
kind of like that. So, we're simulating
what it would be like to put a positive
charge up here.
That's right. That's right.
Pulling the electrons out of the atom.
Wow.
That's quite a
delicious.
Yeah. [laughter]
Most delicious model of the atom, I've
got to say.
Yeah. So, should we um shall we split
the atom?
Why don't you go ahead to be honest? Do
you want me to do it?
You Yes.
Okay. All right. You know what could
happen? A whole bunch of energy could
[laughter] be released.
Yeah. That's right. Ready? One, two,
three.