Dennis Whyte

It's in a solid phase, right?

And then if you heat it up, it's the temperature that typically sets the phase, although it's not only temperature.

So you heat it up and you go to a liquid and obviously it changes its physical properties because you can pour it and so forth, right?

And then if you heat this up enough, it turns into a gas and a gas behaves differently because there's a very sudden change in the density.

Actually, that's what's happening.

So it changes by about a factor of 10,000 in density from the liquid phase into when you make it into steam and atmospheric pressure.

All very good.

Except the problem is they forgot like what happens if you just keep elevating the temperature.

It's good to start doing it.

So it turns out that once you get above, it's approximately 5 or 10,000 degrees Celsius, then you hit a new phase of matter.

And actually, that's the phase of matter that is for pretty much all the temperatures that are above that as well, too.

And so, what does that mean?

So, it actually changes phase.

So, it's a different state of matter.

And the reason that it becomes a different state of matter is that it's hot enough that what happens is that the atoms that make up, go back to Feynman, right?

Everything's made up of these individual things, these atoms.

But atoms can actually themselves be

which are made of nuclei, which contain the positive particles and the neutrons, and then the electrons, which are very, very light, very much less mass than the nucleus, and that surround us.

This is what makes up an atom.

So, a plasma is what happens when you start pulling away enough of those electrons that they're free to