Hi. So, we're going to cover uh chapter 1 sections 1.1 to 1.3 and this is uh chemistry 1151. So, first we're going to start with the very basics just what is chemistry assuming that maybe this is your first chemistry class. Chemistry is the study of matter. Matter is anything that has mass and takes up space. Um, and we call that volume taking up space. So mass is kind of like how much of something there is and volume is how much space it takes up. And matter can be naturally occurring, can be synthetic. Literally everything you can think of that you've experienced is matter. Everything that makes up you. Everything that makes up everything you interact with is all matter, including the air that you breathe. Um in chemistry we're studying how matter is made up. So like what is it composed of? How does it behave? What does it look like? What are its properties? And then most of you are familiar with the chemistry or as being the trans study of transformations of matter. So chemical reactions, how does matter change and um those those types of interactions, states of matter. And this may be a review for you. So feel free to fast forward to move through these videos as you see fit. Um states of matter would be um the solid state is our first one and we want to think about tightly packed particles. So this image is showing the particles really tightly packed kind of in an ordered fashion has a definite volume means that you cannot really change the volume too much of a solid like imagine like your table, your desk or your chair. It is going to keep the same amount of space that it takes up. we can't really compact it. Yes, there are, you know, ways that you can kind of compact some solid materials because there is space in between the particles, but for the most part, a solid is going to have a definite volume. It maintains its shape regardless of the container that it's in. And so, if you were to think about a solid going into like a different container, like if you try to put something into a box that's a solid, it's not going to spread out and take the container shape. It's going to maintain its own shape. And then of course solid particles lie close together in a regular pattern as you can see in the image. What I want you to kind of get in your head though is that solid particles are not motionless. And I like sometimes we like to think about solid particles as being still or frozen. And they're not motionless unless um you're at 0 Kelvin which is called absolute zero. And Kelvin is a temperature measurement. Um it is -273° C. Uh and so it is very very very cold. For example, space is about 2 or 3 Kelvin. So even space doesn't really get this cold. Um, the only way that a set of matter or particles would be totally frozen, not moving at all is at absolute zero. So, think about the chair you're sitting in, the headphones that you have in your ears or over your ears, your hair, your clothing. All of these particles are actually vibrating at some frequency. Um, even if it's a solid. And so that may make you feel a little itchy a little bit, but like everything is kind of having even solids have this little vibrational energy um because nothing is actually still unless it is an absolute zero. So in that image of a solid in your head, take that picture of those really tightly compacted particles that are kind of in a pattern, but vibrate them a little bit so that you really get an idea of what the particles in a solid at room temperature would be like. The next state of matter if we add a little more heat would be liquid. Liquid has a definite volume. So if I have um a one liter container of a liquid, a drink or something like that and I pour it into another container, it is going to stay one liter, right? So a 2 L soda is going to stay 2 L even if I put it into a bucket or to a bigger container. But it does change the shape of the container that it's in. So, if I take a 2 L soda and the shape of it is in that 2 L bottle and I put it into like a bucket or I put it into like, you know, some other container, a bowl or something, it will take the shape of the new container and it's not going to change its volume. It's not going to take up more or less space, but it will change the shape. Uh, and the particles are close together, but they can still move past each other. So, you will see they're not really in a regular pattern anymore. They kind of slide past each other a little bit. Uh, so they have a little more space. It's It's not quite the compactness of the solid, but they can move around a little bit. I like the joke that cats are liquid. So, cats are actually, you know, made of solid things, but they can form the shape of their container really well, right? So, if you ever seen like a cat in like a glass bowl or something, you maybe are familiar with that. So, that is your visualization of a liquid. Particles are definitely moving in a liquid. So, they're moving probably faster than they are or moving more than they are in a solid. Um, especially if we've been heating it up as we go. As you heat something up, the particles move faster. So, liquid usually it's not hard to think about, but those particles are moving and kind of flowing around each other. And then gas is kind of the the last state of matter that we'll talk about. There's another one called plasma, but we don't really interact with that um too much. Gas state is no definite shape. So, if you were to release a gas into a room, it's eventually going to take up the whole space of the room. Um, if if a liquid did this, if we poured water into a um a container, if liquid had no definite shape or volume, then the liquid would fill up the whole container. it would like spread out to fill up the whole container, which is not which would be kind of weird. If I put in like a cup of liquid into like a larger container and all of a sudden it just fills up the whole container. That would be kind of weird. But that's what gases do. If you spray a perfume or something in one area of the room, you're going to smell that kind of throughout the whole area, right? It's dispersing. It's taking up the whole space. So, it has no definite shape and no definite volume. So, it just kind of conforms to whatever container it's in. Gas particles are really, really, really far apart. This image doesn't really quite do it justice. If this image were really true and a, you know, microscopic scale here, you probably would only see one particle in there. Um, gas particles are so far apart and move so fast that if you were riding on a gas particle, like a horse or a car or something, uh, you would only see another gas particle when it ran into you and then you would never see another gas particle. That's how far apart those particles are. They move around really fast and in constant random motion. And we'll talk more about gases later, but they're kind of the opposite of solids. So, not not in a pattern and really really far apart. Physical properties are things that you can observe or measure without changing what that substance is. So, for example, we can see what color something is without changing what it is. You can observe an odor or the state of matter that it's in. Boiling point, melting point, and solubility are a little bit harder physical properties because we do have to do something to them to know that property. So like you have to heat water up to know at what temperature it boils or you have to heat ice up to know what temperature it melts. For solubility, you have to see if something will dissolve in something else. You have to actually do something to see that. But you're not changing what the substance is. When we melt ice, we're not changing it. It's still water. We're just changing the state of matter. So, a physical property is anything that we can measure. Even if we have to do something to it, that is not going to change the chemical composition like exactly what it is like the chemical formula of it. For example, water is H2O even if it's solid. And if I figure out at what temperature it melts, I can get that physical property by melting it, but it is still water. So that's a physical property. A chemical property I guess a physical change is um when you change the material without changing composition. So in order to tell a physical property you can do physical changes. If you do a physical change to tell a property it's a it's a physical property. Um sometimes phys chemical changes also alter physical properties. But if it's only that physical change it's not a chemical change then it's probably a physical property here. So, uh, solid water melting, again, it's still water. Boiling, it's still water, but we're just changing it. Um, changing state is a physical change. Uh, if you were to take a marker and you were to color on a piece of paper, it's still paper, right? And the marker ink is still ink. It just now together. Um, mixing salt and water together, right? Dissolving salt and water. It's still salt. It's still water. They're just mixed together. Now those are physical changes. Uh we'll cover more of those kind of changes a little bit later but in general physical change does not change at the core what those particles are like the composition one oxygen two hydrogens's for example. Chemical properties and chemical changes are different. So chemical properties um are how do we change things into other things. So, a property would tell you if something is like reactive. Another example of a property, a chemical property would be if it is toxic, if it is flammable. We can't really tell those properties unless we actually do that thing. And doing that thing changes what it is. If I ask myself, is this paper flammable? Once I light that paper on fire, it's not paper anymore. It's got totally changed to a new chemical thing. And so if we have like oxygen and hydrogen separately and we do a chemical reaction to make water, whatever property caused it to make water, that's a chemical property because it's turning into something new. And then a chemical change is just a chemical reaction. You're turning something into something totally new. We're going to go really deep into chemical changes and chemical reactions a little bit later in the course. Classification of matter. So we in science cannot just leave it up to each individual person to think of different classifications of all the matter that we interact with. And so we try to come up with these buckets of terms and labels to put stuff in. And yes, there are some gray areas in all of this, but we're going to focus on the basics. And when you see a test question, you need to think about not like, well, sometimes this and that. Just think about the most of the time where would you kind of put this thing? We have two different types of matter. We're going to classify into two main groups. I'll show you a flowchart later, but two main groups. Pure substances or mixtures. So pure substances are only one thing. So think about the ingredient list. So the ingredient list would just be one substance. So if you look on the back of a packet of sugar for example, it would say ingredients sugar. That's it. If you look at the back of baking soda box, ingredients, baking soda, sodium carbonate or bicarbonate, that's it. One thing, purified water ingredients, water. Now, most of your water bottles are not purified. Um, they contain other things, electrolytes and other kind of stuff in there. So if it's like a just purified or distilled water though, like the water we use in the lab, it would be just one ingredient, one substance. This thing has a constant composition. So it doesn't matter how much water you have. Water is always two H's and an O. It doesn't matter how much salt you have, table salt, it's always one sodium and one chlorine for sodium chloride. And it cannot be broken down into other pure substances through a chemical change. We can't break water into hydrogen and oxygen with a physical change. It has to be a chemical change because once we break it down into its pieces, it's no longer water anymore. Now it's hydrogen and oxygen. Both of those are gases and behave very differently from water. Um, a pure substance is one ingredient. Okay, one thing can be an element or it can be a compound. We'll talk a little bit about those in a second. Or you're a mixture. So, you're either pure 100% one thing or you're a mixture. Mixtures are composed of more than one thing. Um, they can have any combination of composition. So, think about like um salt water. Salt water would be considered a mixture. You could have really salty water with a lot of salt and a little bit of water. Or you could have a lot of water and a little bit of salt, but it's still salt water. So, different percentages of salt and water could still make salt water versus like water has to be two H's to 1 O for every water molecule. It's a set composition. And the mixtures can be separated by physical processes. So, if you want to take your salt water and you want to separate it out, you just boil the water off. So, we're separating based on boiling point. The salt has a really high boiling point and really high melting point. So, if you if you're not sure about this, just make some salt water and put it in a a saucepan and just heat it up, boil all the water off. You will have salt left over at the end of the day. Um, so we can separate them easily by like physical processes of physical changes. It's probably a mixture. Um, so example, sugar and water or salt and water is a mixture. And so you can see how the water is kind of surrounding the sugar molecules. So it's dissolving in the water. So that's if I you have sugar water as ingredients would be two things. Sugar water. It wouldn't be sugar water as one thing. We have two different types of molecules here. You have water molecules and we have sugar molecules. So pure substances can either be an element or a compound element. All atoms are the same. All atoms are the same element. So an element would be like oxygen for example like if you have a patient on oxygen or something right the all every atom in that oxygen tank is O is oxygen. Every atom is the same element. A compound is two or more elements together like water. So all molecules, not all atoms are the same, but all molecules are the same composition. So for example, if we have water, it's like every molecule is two H's and an O. But you're just kind of copy pasting that H2O over and over again. And that's all you have in that container is molecules of H2O. that's still pure. It's pure H2O, pure water. A compound is kind of hard to tell from a mixture sometimes. Um, so you'll have to do some practice to kind of figure that out. But definitely ask questions if you're confused of whether or not it's a compound or a mixture cuz those are kind of hard to tell. So here's some examples. Aluminum foil. See how all the atoms are the same substance is? Every atom is aluminum. Nitrogen. Every, even though they kind of come in pairs, they come in molecules. These are called diatomic elements. They exist together, two atoms in one molecule. Even though the nitrogen exists as a molecule, it's still the same atom every time repeated. So all nitrogen. Water is an example of a compound. Every molecule is the same. And again, we're just copy pasting the same molecule over and over again. Or sodium chloride. We're kind of copying pasting the same unit. It's one sodium and one chlorine. And we're just kind of copy pasting one green, one purple, one green, one purple, one green, one purple, one green, one purple over and over and over again to make the substance. So it's pure because it's all one thing, but they have different elements. If it's pure, all one thing, but it's all the same element, then it's just an element. So these two would be elements, and these two would be compounds. So thinking about where we are in this flowchart right now, all things are matter. Can it be separated by physical process? So does it have one ingredient or does it have multiple ingredients? Can it be separated without doing chemical reaction? If it cannot be separated without doing chemical reaction, it's a pure substance. It's got one ingredient. And if you want to take those pieces apart, it is not going to be that same thing again. If you have sugar and you try to take it apart into carbon, hydrogen, oxygen is not going to be sugar anymore. Can it be broken down into simpler substances by chemical reaction? So, can we take that sugar and break it down into carbon, hydrogen, oxygen with chemicals? Yes. Then it would be a compound like sugar or water, right? Can we break water into down to hydrogen and oxygen? Yeah. But through a chemical reaction, not through a physical process. If you can't break it down into simpler substances, like if I take all that nitrogen and I say, "All right, I'm going to separate all the nitrogen." It's still going to be all nitrogen. You can't really separate it further. It's just all nitrogen still. That's going to be your element. So, we're going to talk a little bit more about the mixture side of things. Oh, no, we're not. Uh, so mixture side of things, we'll get into um a little bit later. I I suppose um well, let's go ahead and talk about it now. For some reason, the textbook decided they're not going to do this. So, let me add in a slide here real quick for you. So, a mixture is going to be either homogeneous. Know why they cut this off of this slide here? So, homogeneous mixture or a heterogeneous mixture. Homo means same. So homogeneous mixture is the same throughout. What I mean by that is you can't really tell one part of it is different than the other part of it. So an example would be like um black coffee. And I say black coffee because once you start adding in cream and sugar and that kind of stuff, it can get a little different. But black coffee, hot coffee, cuz iced coffee might be a little bit different. So just plain hot black coffee. The top of it and the bottom of it should be the same. If you're not if you're brewing well, right, you don't have granules of coffee grounds in there, um, would be the same. If you maybe got if you bought yourself a Gatorade at the store, right, you would expect the top of it and the bottom of it to be the same. You don't really expect floaty bits hanging around in there. So homo means the same throughout. You can't really tell there's something different in there. Um, usually salt water would be an example of this. Salt or sugar water. Um, you could probably put some salt in my water and I wouldn't even realize there was anything in there. You could shake it up and I would think that it was just pure water. So, this is really confusing sometimes between um a compound and a homogeneous mixture. So, be careful with that comparison. So, maybe make sure you're asking questions if you're confused as to why what's what. Um the you can separate coffee into you can take oh it's you can take it apart right into caffeine and other tannins and other things Gatorade you can take those apart you can take separate the sugar out there are ways in which you can do that and keep all the things the same thing sugar is still sugar in Gatorade it's just mixed in with the water and other stuff right so that's why it's a mixture and not a compound heterogeneous mixtures are a lot easier to tell this is different throughout so it's got different pieces to it so Like for example, I love I like the example of a pepperoni pizza. Any kind of pizza really like you've got your toppings, you've got your cheese, you got your sauce, you got your crust. There's like defined areas. That's the cheese area. That's a crust area, right? You can clearly see the differences. Um Italian dressing or any sort of oil and vinegar mixture, right? You can see there's a two separate pieces and bits floating around there. Um, orange juice with pulp. There's floaty bits. There's things around in there. So, that's heterogeneous. Heterero meaning different. So, those are the two types of mixtures that you may see in homework or in in practice. Um, and that's kind of hopefully will give you some examples there. But this should be the one slide you can use to do all your classification of matter work. All right, that's sections 1.1 through 1.3. I'll see you next time for the next couple sections.