ELI5: What is plasma as a state of matter?

Plasma is a super hot, soup-like state of matter where electrons have been stripped away from atoms, creating a gas of positively charged ions and negatively charged electrons.

Imagine you have ice, which is solid water. If you heat it up, it turns into liquid water. Keep heating it, and it becomes steam, which is water in a gas form. Now, imagine you keep heating the steam really, really hot – much hotter than your oven can go!

This super-hot gas gets so much energy that the tiny bits that make it up, called atoms, start to break apart. Specifically, the tiny negative things called electrons that are usually stuck to the atoms get knocked off.

Now you have a mix of:

• Atoms that are missing electrons (these are now positively charged ions)


• Lots of loose, negatively charged electrons

Think of it like this: imagine your family is an atom. The parents are the heavy nucleus (positive charge) and the kids are the electrons (negative charge). When you add a lot of energy (like a big argument), the kids (electrons) run away from the parents (nucleus)! Now you have a separated family (plasma).

Examples of plasma include:

• Lightning: The bolt of lightning is a channel of very hot air where the air molecules have been turned into plasma.


• The Sun: The Sun and other stars are giant balls of plasma. Their extreme heat keeps them in this state.


• Neon signs: The glowing light in neon signs comes from plasma inside the glass tubes. Electricity is used to heat up the gas and turn it into plasma.