Hey, everyone. In our journey to understand chemistry, it's first important to define what chemistry is. Now chemistry is the study of matter and the changes it undergoes, with the atom being its basic functional unit. Matter itself is anything that occupies space and has mass, and when it comes to matter, we can group it under 3 types. We're going to say the first one is the simplest type of matter, composed of one kind of atom. That would be our elements. Okay. Now when we say "element," you might have heard of it. If you've taken chemistry before, you might have heard of the periodic table of elements. We'll go into that in greater detail later on, but just realize that when we're talking about an atom, we're often referring to those elements on the periodic table.
Next, we have matter composed of 2 or more different elements that are chemically bonded together. So here we're talking about 2 or more elements, that means we're talking about compounds. A compound is when you have 2 or more elements connected together chemically. Then finally, we have matter that is composed of elements and/or compounds that are physically mixed together. The keyword here being "mixed". So here, this would be our mixtures. A mixture would be the third type of matter. Now that we've grouped matter into these 3 types, let's continue onward and further talk about these groupings.