Classification of Matter - Online Tutor, Practice Problems & Exam Prep

Chemistry is the study of matter, its composition, and the transformations it can undergo. Matter, which occupies space and has mass, is classified into three main types: elements, compounds, and mixtures. Elements are the simplest form of matter, consisting of only one type of atom, such as carbon (C) or oxygen (O₂). Compounds are substances composed of two or more different elements chemically bonded together, like water (H₂O) or glucose (C₆H₁₂O₆). Mixtures are combinations of elements and/or compounds that are physically mixed, not chemically bonded, and can be either heterogeneous (non-uniform, like oil and water) or homogeneous (uniform, like air). Understanding the classification of matter is foundational in chemistry, as it informs the study of how substances interact and change under different conditions.

Introduction to Chemistry Channel

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Classification of Matter

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. Now matter itself is anything that occupies space and has mass. And when it comes to matter, we can group it under three types.

We're going to say the first one is the simplest type of matter that is composed of one kind of atom. That would be our elements. OK, Now we're going to say an 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 oftentimes referring to those elements on the periodic table.

Next, we have matter composed of two or more different elements that are chemically bonded together. So here we're talking about two or more elements. That means we're talking about compounds. So a compound is when you have two or more elements connected together chemically.

Then finally we have matter that is composed of elements and Oregon compounds that are physically mixed together, the keyword here being mixed O here. This would be our mixtures. So our mixture would be the third type of matter. Now that we've grouped matter into these three types, let's continue onward and further talk about these groupings.

Classification of Matter

So When it comes to the classification of matter, it all begins with its composition. We ask ourselves, is it a single composition or a variable composition? Now, if it has a single composition, that means it's composed of a single type of substance, it's not mixed with another one. And if we're dealing with a single composition form of matter, then we label that a pure substance.

Next we ask ourselves, is this separable into simpler substances? If the answer is no, then it represents an element. Now remember, from up above, an element is a type of matter composed of one kind of atom. Now, a good example of this would be Carbon. Carbon uses the symbol C. We'll learn about the symbols and element names later on, but for right now Carbon uses the letter C. It is an element because it's made-up of one kind of atom, a carbon atom.

Now oxygen exists as O2, and although there's two oxygens there, it's still an element because it's still made-up of only one kind of atom, Oxygen atoms. There just happens to be two of them. We also have phosphorus, which in nature is P4, and sulfur, which is S8. The natural forms of these elements will also talk about later on when discussing the periodic table. But for now, realize all of these are elements because each of them is composed of only one kind of atom. Some of them are by themselves like carbon, and in the others there could be multiple of that same kind of atom.

Now, if our pure substance is separable into simpler substances, then we'll see that it's a compound. A compound is composed of two or more different elements chemically connected together. A good example is something we know, water. Remember, water is H2O. It's made-up of two hydrogen atoms and one oxygen atom. We also have carbon dioxide which we breathe out, which is made-up of 1 carbon atom and two oxygen atoms. Then we have something a little bit less known, a natural sugar glucose. Glucose is C6H12O6. It's made-up of different elements together. Carbon atoms or carbon elements, hydrogen and oxygen. So glucose would fall under the definition of a compound.

Now if our matter is composed of variable composition, that means it's different substances mixed together with the keyword being mixed. This means that we're dealing with mixtures. With mixtures, we ask ourselves, does it have a uniform composition where everything looks the same in the mixture, or is it not uniform? If it's not a uniform mixture, it'll be composed of different substances and we can tell them apart. This would be called a heterogeneous mixture.

A great example is oil and water. The saying is oil and water don't mix. That's because if you were to take some water and pour some oil in it, shake it up and then we lie it down on a table or lay it down on a table, eventually be able to tell what part of the mixture is oil and what part is water. Because again, oil and water don't mix, we can tell the different parts involved within the mixture.

Now if it has a uniform composition, then it is a homogeneous mixture. A great example of this is all around us, air. Air is a homogeneous mixture because air is composed of a lot of different things, but all of it looks the same to us. It's composed of oxygen, nitrogen, argon, carbon dioxide, carbon monoxide, as well as other things. It's a lot of different components, but everything looks the same. That is what a homogeneous mixture is.

So remember, when it comes to classification of matter, looking at it from a macro view, we look at its composition first. From there, we go into pure substances and mixtures, which will help us identify the three major types of matter we talked about above. Now that we've gone over matter, let's go on to the next video.

Classification of Matter Example 1

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.

Which of the following statements is true?

• A. Compounds can only be broken down by chemical means.
• B. Gasoline is a pure substance.
• C. Only elements are pure substances.
• D. Milk is an example of a homogeneous mixture.
• E. Concrete is an example of a homogeneous mixture.

Choose the homogeneous mixture from the list below.

• A. Soda
• B. Smog
• C. Trail mix
• D. Bowl of cereal with milk
• E. Pure oxygen and nitrogen gas

Choose the homogeneous mixture from the list below.

• A. Chicken noodle soup
• B. A cup of black coffee
• C. Sand (unfiltered)
• D. Fruit salad
• E. Seawater (unfiltered)

Classify each of the following as an element, compound or mixture.

a) Ammonia, NH3

b) Gold bar

c) Orange juice

d) Wine

e) Saline solution

So here we need to classify each of the following as an element, a compound, or a mixture. For the first one, we're dealing with ammonia, which has the formula NH3. It's made up of nitrogen and 3 hydrogen atoms. It's different elements chemically bonded together, so it is a compound. Next, we have a gold bar. It's made up of pure gold, so it's a pure substance. And because it's just gold, one kind of atom, it has to be an element. Orange juice, it's made up of a liquid portion, sugar, orange concentrate, and pulp. It's different things mixed together, so it's a mixture. The same can be said for wine. Wine typically has in it water, grapes, some sugar, maybe balanced out with some salt. It's different things, again, mixed together. So, it is a mixture. Then finally, we have a saline solution. You see those IV bags in hospitals that are hooked up to patients? Saline solutions traditionally are made up of water and sometimes electrolytes or medication because it's made up of different things together, mixed together, a saline solution represents a mixture. So just remember, when it comes to the classification of matter, we can group it based on its composition.

Here’s what students ask on this topic:

In the classification of matter, how should air be classified?

Air should be classified as a mixture. Specifically, it is a homogeneous mixture, which is also known as a solution. In a homogeneous mixture, the components are uniformly distributed throughout the mixture, and you cannot distinguish one component from another by simply looking at it. Air is composed of a variety of gases such as nitrogen (approximately 78%), oxygen (about 21%), argon, carbon dioxide, and trace amounts of other gases, as well as water vapor and pollutants. These components are mixed so thoroughly that air has the same composition and properties throughout. It's important to note that the individual gases retain their own chemical properties within the mixture. Air is not a compound because the gases are not chemically bonded to each other, and it is not a pure substance because it is made up of more than one element or compound.

What is matter?

Matter is anything that has mass and takes up space. Essentially, it is the "stuff" that makes up the universe. Everything you can see, touch, taste, or smell is made of matter. Matter exists in various states, primarily solid, liquid, gas, and plasma, which are known as the four fundamental states. The state of matter is determined by the arrangement and behavior of its molecules. In solids, the molecules are closely packed and only vibrate in place, giving solids a fixed shape and volume. In liquids, the molecules are less tightly packed than in solids and can move around each other, allowing liquids to take the shape of their container but maintaining a constant volume. Gases have molecules that are far apart and move freely, allowing gases to expand to fill their container. Plasma, on the other hand, consists of highly energized, free-moving ions and electrons and is found naturally in stars, including the sun. Matter can change from one state to another through physical processes such as melting, freezing, condensation, and evaporation, driven by changes in temperature and pressure.

What is the classification of matter?

The classification of matter refers to the categorization of substances based on their physical and chemical properties. Matter can be classified into pure substances and mixtures. Pure substances have a fixed composition and can be elements or compounds.

• Elements are the simplest form of matter that can't be broken down by chemical means and consist of only one type of atom, like oxygen or gold.
• Compounds, on the other hand, are substances formed when two or more elements are chemically bonded together in a fixed ratio, such as water (H₂O) or sodium chloride (NaCl).
• Mixtures are combinations of two or more substances that are not chemically bonded and can be separated by physical means. Mixtures can be homogeneous or heterogeneous. Homogeneous mixtures, also known as solutions, have a uniform composition throughout, like saltwater. Heterogeneous mixtures have distinct regions of different composition, such as a salad or a rock with various minerals.

Understanding the classification of matter is fundamental in chemistry as it helps in identifying substances and predicting their behavior during chemical reactions.