So if we take a look at this example question, it says consider the following substances. We have Gatorade, crystalline sugar, lead wire, and salsa, and it looks like our option choices are talking about pure substances or homogeneous mixtures. So let's go through each one and identify what we have.

Gatorade. We all know that this is an energy drink, and it looks like just a single colored liquid, sometimes white, sometimes blue, sometimes red, leaving yellow. But if we look closer into Gatorade, we'll see that Gatorade is composed of water, sugar and of course what's important, electrolytes. But all of it looks the same. It has a uniform composition. We can't tell them apart. So Gatorade is an example of homogeneous mixture.

Next we have a crystalline sugar. Don't get confused by the word crystalline, that really isn't important. It's just talking about the organized structure of the sugar itself. Now, up above we talked about biological sugar in the form of glucose, right? So crystalline sugar is pure sugar. You can think of glucose as a good example. Up above we said that glucose was a compound, but more importantly, it was a pure substance. Here we're assuming that it's just pure sugar here by itself, not mixed with anything.

Lead wire. Here we're just dealing with one type of atom, lead. We're not dealing it mixed with anything else. The entire wire is made-up of just lead. So this would be an element and more importantly, a pure substance.

Finally, we have salsa. So salsa can come with a lot of different things besides the base tomato part of it. We could have corn in there, or green peppers, or onions. All we know is that when we look at salsa, no matter what it is, we can tell it has different components in it and because we can see the different parts of it, it is a heterogeneous mixture.

From our choices, we can see A doesn't work because one and two. Two is a pure substance, but not one. One and two were homogeneous mixtures. No, only one was a homogeneous mixture. Out of the two, two and three are pure substances. We did say that one is a homogeneous mixture. We said that too. D can't be the answer because we found out that option C was the correct choice.

So remember, when it comes to classification of matter, think of it in terms of composition. From there, we can separate it further into the three main types that we talked about above. Now that we've done this example question, let's move on forward and continue our discussion on matter and its classifications.