Gas Facts for Kids

Gas is an essential state of matter. The other three are solid, liquid, and plasma. Gas can comprise individual atoms, elemental molecules, or compound molecules. Gas mixtures contain a range of pure gases. Gas separates particles, which makes it invisible to the eye.

Gas Facts for Kids:

  • Gas is a common state of matter
  • Pure gases comprise just one atom
  • Hydrogen is the lightest, most ample, and explosive gas on the planet.
  • Natural gas is the cleanest-burning hydrocarbon.
  • Hydrogen gas is an example of an elemental gas.
  • Elemental gases are made up of two or more of the same atoms joined together
  • Nitrous oxide is a gas that is used in hospitals and can be used in racing cars.
  • We have to have gas to live.
  • Oxygen gives the body energy.
  • Carbon dioxide (Co2) is used to help plants to make food through photosynthesis.
  • When hot gases combine, this can make fire.
  • Natural gases are even lighter than the air we breathe.
  • To get natural gas, people have to drill thousands of feet into the Earth.
  • Helium is used in balloons because it does not catch on fire and is safer than hydrogen.
  • The ozone layer is made up of what is called an oxygen allotrope.  An oxygen allotrope means that the oxygen has three different atoms of oxygen that are joined together.

What Is Gas?


Gas is a substance that is in the air that flows around.  Sometimes, gas can be put into a container so that it can be kept.  Even if gas is put into a container, if the container is opened, the gas can get out very quickly and spread out around the area that it is in.

Since gas is a state of matter, it is part of matter that does not have any specific type of shape and it just flows freely.

Gases are found all around us and the air that we breathe is full of gas.

How is Gas Measured?

Shuttle imagery of re-entry phase

Gas cannot be measured by its shape or its volume because it does not have weight or a specific shape.

Gas has to be measured using math because gas is made up of different molecules.  Besides pure gas, all other gases are made when two atoms are joined together, and a molecule is formed.

Pure Gases

Pure gases are gases that are made up of only one atom.  Our air, for example, has different pure gases.

Pure gas is made up of atoms that are individual such as the gas neon.  It can also be made up of elemental molecules that are made of one atom such as oxygen.

A compound molecule that has many different atoms can also contain pure gas.  One example of this is carbon dioxide.

Elemental Gases

Elemental gases are gases that are made up of two or more atoms that are the same atom, but they are joined together.  A great example of an elemental gas is hydrogen gas.  Hydrogen gas is made up of two hydrogen atoms and even though they are the same atom, there are two of them.

Compound Gases

Compound gases are gases that are made up of different atoms.  There must be at least two atoms and they have to be different to be compound gases.  A great example of a compound gas is carbon dioxide.  Carbon dioxide is made up of a carbon atom and two oxygen atoms.

Remember, there have to be at least two different kinds of atoms to make it a compound gas.

How Is Gas Different Than Water?

Gas is similar to water because it can flow but the difference is that liquid stays in one place while gas does not.  Gas moves around all the time and it expands and goes in different directions to fill the area that it is in.

If you put gas into a container and forget to put the lid on, the gas will not stay in the container and it will flow away.


Matter is anything that takes up space and has mass.  Matter is made up of different atoms, sometimes millions and millions of them.  Matter is also made of molecules and the molecules combine together in order to make different objects such as things we can touch or play with like a ball or a shoe.

There are three different types of matter:

  • Solid
  • Liquid
  • Gas

Today, we are talking about the third kind of matter, gas.

Classification of Gases

Gases can be classified as either artificial or natural.

  • Artificial gas-Artificial gas is gas that is made by people.  People use different chemicals to make different gases.  These gases can be hurtful to nature and can damage things such as the ozone layer that we need to help protect us from the sun’s radiation.
  • Natural gas-Natural gas is a gas that is found in nature and made by nature.  Some of the natural gases include nitrogen and oxygen.  We use these gases to help us to breathe and live.


When we breathe in the air, we are breathing in different kinds of gases.  Our air is made up of 1% argon, 78% nitrogen, and 21% oxygen.  These gases help us to be able to breathe and help us to be able to live.  If the gases would change too much, we would not be able to breathe and we would not be able to live on Earth.

Natural Gas

Natural gas is a type of gas that is used to help make electricity.  This type of gas is used for many things such as heating, helping us to cook, and helping us to be able to drive our cars and other vehicles.

It’s a nonrenewable resource which means that once it runs out, we will not be able to replace it or make more of it.

Natural gas is oil and coal and is also called fossil fuels.

Global warming is caused mostly by human activities such as burning fossil fuels.

Is the burning of fossil fuels affecting the global climate and our planet?

Most fossil fuels are made of plants and animals that have died or from trees and algae.  When natural gas is used, it has to be taken from deep into the ground and brought to the surface with pipes and pumps.

Natural gas is a mixture of many different types of gases such as:

  • Propane
  • Carbon Dioxide
  • Methane
  • Nitrogen
  • Hydrogen Sulfide
  • Ethane
  • Oxygen

Noble gases

Noble gases are the gases that are found in the period table.  They are also called elements.  These gases are found in the 18th column of the period table.

Noble gases are also called inert gases because they are made up of atoms and electrons.

Noble gases include:

  • Argon
  • Krypton
  • Helium
  • Neon
  • Xenon
  • Radon

What Are Noble Gases Made Of?

Noble gases are like many other gases because they have no color and they have no smell.  The difference between noble gases and other gases is that they do not react with other elements to form compounds.

Another interesting thing is that noble gases have a shell that is made up of electrons.  All of the noble gases have only eight electrons, except for helium that only has two.

Plenty of Gases

Hydrogen is the gas that there is the most in the world and the second gas is helium.  On Earth, these noble gases are considered very rare except for argon because argon makes up 1% of the atmosphere of the Earth.

How Fast Do Gases Move?

Gases move very fast.  Most gas can move around 1,6000 kilometers per minute.  Even though we do not know how fast this is by reading it, we can learn that a plane only goes 885 kilometers per minute and so gases are even faster moving than an airplane!

Gas Particles

When gas particles flow around the atmosphere, they sometimes hit into each other or other gases.  When this happens, the gas particles just bounce in another direction from each other because the force is not strong enough to keep them together.

What is a Vapor?

Gas vapor is a gas that has water particles that have gone back into the atmosphere after being on the surface of the Earth.  This vapor is gas and when it gets heated, water can escape from the gas and form a vapor.

One example of this is mist.  Mist is actually gas that mixes with the air and cools down.  When it cools down, it causes mist to form.  A gas that is liquid when it is at room temperature is a vapor.

How Does Gas Move?

When gas gets heated, it gets bigger.  The gas particles move faster and further apart when they become hot.  A great example of this is a balloon.  When we fill up a balloon, we use gases from inside of our bodies to blow the balloon up.

If you would heat a balloon over fire or steam, the balloon would eventually explode or pop.  This happens because the air inside gets so hot that the particles get bigger and faster and eventually the balloon is not strong enough to hold the gas in.


Gas can have a lot of pressure.  If we think about a geyser, sometimes, they are made up of just gas.  When the gas is put into a small area, it can build up the pressure because it wants to be let out.  When a geyser erupts, this is gas that has been under a lot of pressure and wants out of the hole.

Another example is soda.  When you shake a soda, what will happen?  The gas inside of the bottle will build up and up until the soda lid will blow off, or, if you happen to open it, the soda will flow out of the bottle with great force.

When there are bubbles, most of the time, this is gas pressure that has begun to build up and is being released in the form of bubbles.

Why Are Gases Important?

There are many reasons gases are important such as:

  • Helping people to breathe that can’t breathe on their own (oxygen)
  • It can be used for anesthesia (nitrous oxide) which helps people not to be in pain during surgery.
  • Electricity
  • Refrigerators
  • Stoves
  • Light Bulbs
  • It can help us to make things such as clothing or glass.
  • Can fill our balloons.
  • Is found in food such as soda.
  • It can be used for grilling and cooking.
  • It can help with fuel for our cars.
  • Used in lighters.

What Did You Learn?

  • What is gas?  Gas is a form of matter that is freely moving, has no smell and we cannot see it.
  • Is gas important?  We cannot live without gas.  We use gas to breathe and to do everyday things that we need doing around our house such as cooking, heating things, and even for medical reasons.
  • Are there different kinds of gases?  There are many different kinds of gases such as compound gases, natural gas, noble gases, and more.
  • Does gas move?  Gas moves very fast.  Gas can even move faster than an airplane.
  • What happens when gas is heated?  When gas is heated, it moves even faster.  Heat causes the gas to expand and to move faster and faster.