Oh, my God, oh, oh, wow, oh, oh, wow.

Oh, wow.

Oh, my. Hello, you're listening to the Science of Everything podcast episode 23, chemical reactions, and I'm your host, James Fodor.

In today's episode, we're going to have a look at chemical reactions, how they're represented in the form of chemical equations, we'll give some examples, and then I'll talk about various aspects of how chemical reactions work and why they happen, including such topics as thermochemistry,

collision theory, reversible reactions, and I'll also go through some of the different types of chemical reactions.

Chemical reactions is obviously a very large topic that occupies a substantial portion of chemistry,

so this is only really an introduction today.

Also, I recommend that you have some

background in basic chemistry topics like atoms and molecules, compounds, chemical bonding, that

sort of thing. Episode 9, matter and molecules and episode 15, chemical bonding would be useful

prerequisites for that sort of thing. Okay, so let's get into it. Okay, first of all, what is a

chemical reaction? Chemical reaction is also called chemical change is a process by which one or more

pure substances are converted into one or more different pure substances. A pure substance is basically

an element or a compound, so it could be hydrogen, gas,

could be water, it could be sodium chloride, whatever. So whether it's covalent or ionic, or a single

element, or a giant molecular compound, like diamond, whatever. As long as it's a pure substance,

it has a specific chemical formula that you can apply to it and given properties, then it's a pure substance. If you have

one or more pure substances and then something happens, there's some kind of process that goes on,

and they're converted into one or more different pure substances, we call that a chemical reaction.

So when water evaporates or when water freezes, or when something gets heated up to a high temperature, when a rock

gets broken up into small pieces, none of those are chemical reactions or chemical changes,

because the substance of which the rock or the water is made up has not changed.

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