Matter is all around you. Matter is anything that has mass or takes up space. If it’s made up of atoms or molecules, it’s matter!

Even though matter is everywhere around the universe, it usually only comes in just a few forms. Scientists have discovered five states of matter so far: solid, liquid, gas, plasma, and Bose-Einstein condensates. The most common are solids, liquids, and gases.

What’s the difference between these different states of matter? It’s all about the physical state of their atoms and molecules.

For example, a water molecule (H2O) consists of two hydrogen (H) atoms and one oxygen (O) atom. Whether its physical state is a solid (ice), a liquid (water), or a gas (vapor), it’s still water made up of H2O molecules.

Solids have a particular size and shape. The atoms and molecules in a solid are packed together tightly and do not move much. Common examples of solids are an orange, a rock, or a coin.

Liquids have a specific size or volume, but no particular shape. Liquids take the shape of whatever container they find themselves in, whether it’s a soda bottle or a creek bed. The particles in a liquid are not packed as tightly as those in a solid. They tend to move around much more freely. Common examples of liquids are water, milk, and juice.

Gases tend to be harder to identify, because they have no color, shape, or size. The particles in a gas move quickly and freely and tend to have a lot of space between them. Gases can take the shape of any container. Common gases include oxygen and carbon dioxide.

To change from one state of matter to another, the physical properties of the matter must change. This usually happens through changes in temperature, pressure, or other physical properties.

For example, when solid water (ice) gets hot, it melts and turns into liquid water. The reverse of this process is freezing. When liquid water gets hot enough, it vaporizes into a gas. When water vapor cools off, it condenses back into liquid water.

It’s also possible for a solid to turn directly into a gas without first changing into a liquid. Dry ice, for example, is frozen carbon dioxide. When it heats up, it changes directly back to carbon dioxide gas in a process called sublimation.

20 Join the Discussion

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  1. I think that today’s wonder really does matter!!! When I was in fourth grade, we did a big unit on matter and we did an experiment where we heated up ice cubes, and the ice went from a solid to a gas. Also we did an experiment where we took a cookie tray and put it over the rising gas. and then it turned back into liquid again and it dripped down. This experiment represented the water cycle.

    I love making freezer popsicles!! We have a special popsicle make that has the shape of storebought popsicles, and you fill it up, we usually do lemonade. Then you put the lid on, which is the stick. It’s a delectable treat!! :)

    I think that tomorrow’s wonder is going to be about s’mores because they made up of chocolate, graham crackers, and marshmallows.

    • Happy Wednesday, Meredith! That sounds like a GREAT experiment to show how the states of matter can change so much! We bet those popsicles you and your family make are really awesome, too! They might come in handy in Wonderopolis today…it’s going to be another hot summer day! :-)

  2. I agree! I t is super hot outside, today. I’m having one of the popsicles I put in the freezer this morning. It tastes so cold and sweet!! :)

    • That’s a GREAT way to stay cool and give your tummy a treat, Meredith! We’re glad you enjoyed that homemade popsicle! :-)

    • Hi, Rashell! Thanks for being such a GREAT Wonder Friend! You can learn more about what matter is and the different states of matter (like solids, liquids and gasses) by exploring this Wonder of the Day®! We encourage you to visit the information here again to help you understand matter a little better! :-)

    • We hope you learned LOTS of cool new facts about matter, Rashell! Thank you so much for re-exploring this Wonder and leaving us another awesome comment! :-)

  3. We did this matter thing in grade 3 but it was disgusting we put chocolate in our mouths then let our body heat turn it into a liquid then we did not suck the chocolate instead we spit it out on a plate then wait until morning then it turned into a soild and another one was that we lit a candle and the wax then turned into liquid and the fire turned into gas and later it cooled then the wax turned into soild again.

    • WOW, that sounds like a great way to see all the different forms of matter, Johno! Liquid, solid and gas! Thanks for sharing your comment with us! Sometimes even the craziest science experiments teach us something new! :)

  4. That is pretty useful for me because my class and I are studying the unit into What Is Matter !!! That is pretty cool actually.

    • How great, Mike H! We’re excited that our science Wonder is a perfect connection to the unit you’re studying! We’re very proud of all the WONDERing you’ve been doing! Thanks for sharing your very cool comment! :)

  5. I sure my friend will visit this website. Actually my teacher is the one who showed us this website. Thanks for making many wonders and I sure I will learn a lot !!! ☺ ☻ ☺ ☻

    • HOORAY, we hope you and your Wonder Friends have a great time at Wonderopolis! There is so much to do that the WONDERing doesn’t have to end anytime soon! Thanks for sharing your comment with us, Mike H! We hope to see you very soon! :)

  6. I learned that matter really does matter! I learned a lot about solid, liquid, and gas. We liked that the video showed us the difference between solid, liquid, and gas and how they can change their states of matter. We learned that solids can turn into liquids with increasing temperature. We learned that we breathe in oxygen and breathe out carbon dioxide.

    • Great work, Tigers2! We are so glad you summarized what you learned with us today – matter sure does matter! It surrounds us – even we are made up of matter! Thanks for joining us today, we hope to see you soon! :)

    • Hi Zachary! Matter is made up by mass. Mass just exists and is more of a definition of it rather than an explanation. Thanks for WONDERing with us! :)

    • Did you mean ‘what is matter made of’ or ‘what made matter’???

      I’ll try to touch on both…

      All matter is made of atoms. There are over 100 different types of atoms.

      Atoms in turn are made up of sub-atomic particles: electrons, protons, neutrons and a number of other particles (quarks, leptons, hadrons, baryons, mesons).

      There are related things called ‘force carriers’ – photons, gluons, bosons and gravitons (the existence of gravitons hasn’t been proven yet. The existence of the long-theorized Higgs Boson was recently ‘confirmed’ at the Large Hadron Collider in Europe)

      Whether these sub-atomic particles are made up of even smaller things, I’m not sure what the researchers say. There certainly are several theories, none of which has been accepted universally by all researchers.

      For more info, start at

      As to what made matter .. we know less about that. The most common idea is that everything came into existence when the ‘Big Bang’ occurred. If matter existed ‘prior’ to the Big Bang, we do not know for sure (and whether time itself existed prior to the Big Bang is another topic!) There may have even been more than one Big Bang. There are many ideas about the Big Bang, but at this point we do not know for sure.

      As to *why* matter exists .. we know less about that than anything. Many believe there is a larger force in play here, something we refer to as God.

      • Thank you for spending time WONDERing with us about matter today, Bob! We appreciate all of your insight! We hope you have a WONDERful day! :)

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Have you ever wondered…

  • Does matter really matter?
  • What is the difference between solids, liquids and gases?
  • Why does matter change from one state to another?

Wonder Gallery

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Try It Out

Ready to see the states of matter firsthand? Head to the kitchen for some fun, easy experiments that will require an adult. So find a friend or family member to help you with one or more of the following activities:

  • Can you find or make water in all its states in your kitchen? Liquid is easy! Just turn on the tap and pour yourself a glass of water. Solid is also easy, if you have a freezer with ice in it. Grab an ice cube and compare water in its solid form to the liquid water in your glass. Although there is water in the air around you, you can’t really see it. To see liquid water vaporizing into a gas, put some water into a pan and bring it to a boil on the stove. Those bubbles you see in the pan? That’s liquid water turning to a gas and escaping into the air!
  • You already know that liquid water changes to a solid (ice) when its temperature drops low enough. Do you think all liquids freeze at the same temperature? Do your own experiment to find out. Grab four cups and fill each with a different liquid. We suggest using water, saltwater, milk, and fruit juice or soda. Put them in the freezer and check on them every 15 minutes or so. Which freezes first?
  • For a challenge, do some Internet research to learn what it is about the different liquids that makes them freeze at different temperatures. Then, if you want to turn your experiment into a tasty treat, follow these directions to create your own homemade freezer popsicles! We bet you didn’t know science could be so fun and tasty, did you?

Still Wondering

Check out Science NetLinks’ The Water Cycle lesson to learn more about the continuous cycle that water undergoes as it changes form.


Test Your Knowledge

Wonder What’s Next?

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