What Is Matter? Objects and Materials
Matter is anything that has mass and takes up space (volume). Every object you can touch, every liquid you can pour and every gas you breathe is made of matter. In brief: a wooden chair is an object, wood is the material it is made from, and both are matter, while light, heat and sound are not.
Chemistry starts with a simple distinction: objects are things with a shape and a purpose, and materials are what those objects are made of. This article explains what matter is, how to tell objects from materials, how to test whether something counts as matter, and how our ideas about matter developed.
What is matter?
Matter is defined by two properties. It has mass, which is a measure of how much substance is present, and it has volume, which is the amount of space it occupies. If something lacks either property, it is not matter.
Matter exists in different forms, called states: solid, liquid and gas. A block of ice, a glass of water and the water vapor above a kettle are all the same kind of matter in three different states. Air is matter too, even though you cannot see it: a balloon filled with air is heavier than an empty one and takes up space.
What is the difference between an object and a material?
An object is a particular thing with a definite shape, such as a spoon, a window or a coin. A material is the substance an object is made from, such as steel, glass or copper. Many different objects can be made of the same material, and one object can be made of several materials.
| Object | Main material | Why this material? |
|---|---|---|
| Drinking glass | Glass | Transparent and does not react with drinks |
| Cooking pot | Stainless steel or aluminum | Conducts heat and is strong |
| Electrical wire core | Copper | Conducts electricity well |
| Shopping bag | Plastic | Light, flexible and waterproof |
| Pencil body | Wood | Easy to shape and comfortable to hold |
| Bicycle tire | Rubber | Flexible and gives grip |
Notice that the same object can be built from different materials. A cup can be made of ceramic, glass, paper or metal. The material is chosen because of its properties, which later articles describe in detail.
How can you test whether something is matter?
You can use two simple questions. Does it have mass? Does it take up space? A practical way to check is shown in the following steps.
- Weigh an empty, deflated balloon on a sensitive scale and note the reading.
- Inflate the balloon and weigh it again. The reading is slightly higher, so air has mass.
- Notice that the balloon is now larger, so air also takes up space.
Both tests are positive, so air is matter. A second example is a stone placed in a measuring cylinder with water. The water level rises, which shows that the stone occupies space. Its mass can be measured on a balance.
Examples of matter and non-matter
Some things look physical but fail the test. Light, for instance, has no mass in the sense used here and does not occupy a volume the way an object does. The following table sorts common examples.
| Item | Has mass? | Takes up space? | Matter? |
|---|---|---|---|
| Iron nail | Yes | Yes | Yes |
| Orange juice | Yes | Yes | Yes |
| Air in a tire | Yes | Yes | Yes |
| Sunlight | No | No | No |
| Sound | No | No | No |
| Heat | No | No | No |
Ideas, feelings and shadows are not matter either. A shadow is simply an area where light is blocked.
How do we choose a material for an object?
Engineers and designers compare materials by their properties. A raincoat needs a waterproof, flexible material. A bridge needs a strong material that does not bend easily. A window needs a transparent one.
Worked example: choosing a material for an oven handle
Suppose a pan handle must not become too hot, must not melt at cooking temperatures and must be easy to grip. Three candidates are compared.
- Copper conducts heat very well, so the handle would become hot quickly. It is a poor choice.
- Ordinary thin plastic is a poor conductor of heat, but many plastics soften or melt in a hot oven. It is unsuitable for oven use.
- Wood or heat-resistant plastic conducts heat poorly and tolerates moderate temperatures, so it suits a handle on a stovetop pan.
The best choice depends on the use, which is why cookware handles are often made from heat-resistant plastic, wood or hollow stainless steel.
How did ideas about matter develop?
Ancient thinkers asked what everything is made of. In ancient Greece, Democritus is traditionally credited with the idea that matter consists of tiny indivisible particles, which were later called atoms. Aristotle, by contrast, favored the view that matter is continuous and made from combinations of a few basic elements.
In the early 1800s, John Dalton proposed an atomic theory that explained chemical observations, such as why substances combine in fixed proportions. Today we know that atoms contain smaller particles, and that matter is built from a limited number of kinds of atoms. A key step in the 1700s was the work of Antoine Lavoisier, who showed with careful weighing that mass is conserved in chemical changes.
Which mistakes are common?
Mistake 1: Thinking that gases are not matter
Gases have mass and volume. Air resistance, wind and inflated tires all show that gases are real matter.
Mistake 2: Mixing up object and material
A spoon is an object, and steel is the material. Saying that “spoon is a material” confuses the two ideas.
Mistake 3: Calling energy matter
Light, heat and sound are forms of energy or waves, not matter. They do not have mass in the everyday sense and do not fill a container the way a gas does.
Mistake 4: Thinking that small amounts of matter do not count
A single dust grain or a drop of water is matter. The amount can be very small, but it still has mass and volume.