Confounding compounds

In chemistry we talk about compounds all the time. We use them to explain other concepts, like types of reactions or separating mixtures. But if you don't know what a compound actually is it would be tricky to know what on Earth we are talking about.

We know that an element is the simplest form of matter. You can't break it down any smaller with doing some kind of nuclear reaction and those tend to not be very compatible will being alive later o do more chemistry. All of the elements are listed on the Periodic Table, and if it isn't on the Periodic Table it isn't an element (sorry Earth, Wind, Water and Fire). Elements have distinct properties that are different from the properties of all of the other elements. That's how we can tell them apart.

But, something special happens when you get two elements to stick together, they become a new thing with completely different properties than either of the elements you started with. For example, sodium is a metal that reacts explosively with water and chlorine is a very poisonous gas. But, when they are stuck together to make sodium chloride they become a white crystal solid that is actually necessary for life.

These elements-stuck-together are compounds. The elements get stuck together in a couple of different ways, but once they are stuck together you can't get them apart by cutting, or sorting, or filtering or any other physical method. You have to do some kind of chemical reaction to get them back apart. That's what makes them different from just mixtures, where the stuff is mixed together but not chemically stuck together. Mixtures you can take apart without needing a chemical reaction.