What is Matter? - Second Grade Science
Everything you see, touch, smell, and breathe is made of matter. From the solid desk you lean on and the cool water you drink from a glass to the invisible air that fills your lungs when you run, matter makes up all the physical stuff in the universe. Matter comes in millions of shapes, sizes, colors, and textures, yet every single piece of matter shares two fundamental qualities: it has mass and it takes up space.
The Two Rules of Matter
To determine whether something is matter, scientists check two essential characteristics. If an object passes both of these rules, it is matter.
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| THE TWO RULES OF MATTER |
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| 1. MATTER HAS MASS 2. MATTER TAKES UP SPACE (VOLUME) |
| Mass is the amount of Volume is the physical room an |
| matter inside an object. object occupies in space. |
| You can measure it on Two objects cannot occupy the |
| a balance scale in grams. same space at the exact same time. |
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Rule 1: Matter Has Mass
Mass is the quantity of matter an object contains. A heavy bowling ball has a large amount of mass, while a fluffy dandelion seed has very little mass. Even things that feel extremely light, such as a strip of tissue paper or a single grain of sugar, have mass. You can verify this by placing hundreds of them on a sensitive balance scale, watching the scale tip down.
Rule 2: Matter Takes Up Space
Every object takes up a certain amount of space, which scientists call volume. When you get into a bathtub filled to the brim with warm water, the water level rises and spills over the edge. This happens because your body is matter and takes up space, pushing the water out of the way.
Atoms: The Tiny Building Blocks of Matter
All matter is constructed from microscopic building blocks called atoms. Atoms are so unimaginably tiny that millions of them could fit across the period at the end of this sentence.
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| HOW ATOMS COMBINE TO MAKE MATTER |
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| ( * ) + ( * ) ======> [ Molecule ] |
| Single Atoms Bond Molecules Cluster |
| to Form Objects! |
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How Atoms Join Together
When atoms bond with other atoms, they form larger clusters called molecules. For example, two atoms of hydrogen combine with one atom of oxygen to make a water molecule. When billions of these molecules group together, they create the drops of rain you see sliding down a window pane.
What is NOT Matter?
While almost everything around you is matter, some things that exist in our world are not made of matter. Non-matter consists of forms of energy and abstract ideas that do not have mass or take up physical room.
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| MATTER VERSUS NON-MATTER |
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| MATTER (Has Mass & Takes Up Space) NON-MATTER (Energy & Ideas) |
| - Wooden chair - Sunlight |
| - Glass of orange juice - Heat from a radiator |
| - Oxygen gas in a balloon - Sound of a whistle |
| - Ocean water - Thoughts and memories |
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Energy Is Not Matter
Light, heat, and sound are forms of energy. When sunlight fills a room on a bright morning, the room becomes illuminated, but the sunlight does not add any weight to the room, nor does it push the air or furniture aside. When a radio plays music, sound waves travel through the air to your ears, but sound itself has no mass.
Thoughts and Feelings
Your imagination, memories, and emotions are very real parts of your human experience, but they are not made of physical atoms. You cannot weigh happiness on a balance scale or measure the volume of a dream in milliliters.
Proving Invisible Air is Matter
Because air is invisible, it is easy to wonder whether air is truly matter. Scientists can perform simple demonstrations to prove that air has mass and takes up space.
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| PROVING AIR TAKES UP SPACE |
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| Empty Cup Pushed Straight Down Into Water Bowl |
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| | | <-- Inverted plastic cup |
| | [AIR] | <-- Trapped air pocket |
| ~~~~|_______|~~~~ |
| ~~~~~~~~~~~~~~~~~ <-- Water cannot enter the cup! |
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The Inverted Cup Demonstration
If you push an empty clear cup straight down upside-down into a bowl of water, the water will not fill the cup. The trapped pocket of air inside the cup holds the water out because the air takes up physical space.
Weighing Balloons
If you balance two empty deflated balloons on opposite ends of a balance scale, they hang level. If you inflate one balloon with air and reattach it, the inflated balloon sinks lower. The air trapped inside adds measurable mass to the balloon, proving air is matter.
Chapter Review Exercises
Question 1: What are the two essential characteristics that something must have in order to be classified as matter?
Question 2: Explain why sunlight and the sound of a bell ringing are not considered matter by scientists.
Question 3: Describe how you can prove that invisible air takes up physical space using a clear cup and a bowl of water.
Question 4: What are the tiny microscopic building blocks that combine to form all the matter in the universe?
Solutions and Explanations
Solution 1: In order to be classified as matter, something must have mass (contain a measurable amount of material) and take up space (have volume).
Solution 2: Sunlight and the sound of a bell are forms of energy rather than matter. They do not contain physical atoms, have no measurable mass on a scale, and do not displace or take up physical room in space.
Solution 3: You can prove air takes up space by turning an empty clear cup upside-down and pushing it straight down into a bowl of water. The water cannot enter the cup because the pocket of air trapped inside occupies that physical space and blocks the water from entering.
Solution 4: The tiny microscopic building blocks that make up all matter are atoms. Atoms bond together into molecules, which cluster by the billions to build everyday objects like rocks, water, and living organisms.