Solids, Liquids, and Gases

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Solids, Liquids, and Gases

• By Neesa Howard

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Overview

• Materials exist as solids, liquids, and gases and
  sometimes as a mixture of the three states of
  matter.
• A force of some kind must be put on the material
  in order for it to change from one state to
  another.
• Examples pressure or temperature

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Solids

• A solid keeps its shape unless a force is put on
  it. Some examples of force are
• Pushing
• Temperature
• Cutting
• The molecules in solids are packed very tightly
  together and do not move around very much.
• Solids can, book, sand, stapler, person, phone,
  computer, desk, pencil, rubberband

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Liquids

• Liquids
• Take the shape of the container they are put in.
• Are pulled by gravity to the bottom of the
  container and fill it as evenly as possible.
• Might change shape, but never volume.
• The molecules in a liquid are more free to move
  and are not packed as tightly together as those
  in a solid.
• Liquids water, Coke, cooking oil, vinegar,
  gasoline, milk, honey, syrup, Mountain Dew

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Gases

• Gases
• Fill the container they are in or just keep
  spreading out.
• Do not keep their shape or definite volume.
• The molecules in a gas are spread far apart and
  move freely about the container or atmosphere.
• Gases oxygen, carbon dioxide, helium (in a
  balloon), air in a bicycle tire

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Solids into Liquids

• When you heat some solids, they melt and become
  liquids.
• Melting Point the point at which a material
  melts (different depending on substance).
• For example
• The melting point for water is 0 Celsius. This
  is when (solid) ice turns into (liquid) water.
• Butter is solid at room temperature but when
  heated, it becomes a liquid!

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Dissolving

• When you mix solids and liquids
• Sometimes one will sink, while the other will
  float.
• Other times, you will notice that the solid
  disappears. The solid is actually dissolving into
  the liquid.
• When solids dissolve into liquids a solution is
  formed.
• For Example
• When you make Kool-Aid, the powder mix dissolves
  in the water.
• Next, you add sugar and it too dissolves.
• If you add too much sugar you have reached the
  saturation point and no more sugar will dissolve.

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Solid to Liquid to Gas

• When something is solid, the molecules are packed
  tightly and vibrate slowly.
• When the molecules are heated, they vibrate
  faster and begin to spread out forming a liquid.
• If the liquid is heated even more the particles
  vibrate so fast that they begin to escape from
  the liquid thus forming a gas.

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How Water Changes States

• Water is solid when the temperature is under 0
  Celsius.
• At 0 Celsius, water becomes a liquid and remains
  liquid until it reaches 100 Celsius.
• At 100 Celsius, the liquid becomes a gas and
  evaporates into the air.
• The force acting upon the water in this case is
  temperature.

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Reversible and Non Reversible Changes in Matter

• Some changes are reversible, which means that you
  can change them back.
• Examples Taking (liquid) water and freezing it
  so that it becomes (solid) ice. You can allow the
  ice to melt and it will become liquid once again.
  
• Other changes are non reversible, which means
  that they can not change back to their original
  state.
• Examples If you light a match the tip of the
  match goes from solid to gas but can not go back
  to solid because the molecules have escaped.

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Quiz Yourself

• _____ keeps their shape unless a force is acted
  upon it.
• _____ have no fixed shape.
• _____ take the shape of the container it is in.
• What would happen to the gas inside a balloon if
  you popped it?
• What is it called when a solid disappears into a
  liquid?
• What is it called when the molecules in a gas
  disappear?

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Quiz Answers

• Solids keeps their shape unless a force is acted
  upon it.
• Gases have no fixed shape.
• Liquids take the shape of the container it is in.
  
• What would happen to the gas inside a balloon if
  you popped it? The gas would escape into the
  atmosphere!
• What is it called when a solid disappears into a
  liquid? The solid is dissolving and forming a
  solution.
• What is it called when the molecules in a gas
  disappear? Evaporation

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Test Your Knowledge

• Visit the site below to see if you know your
  states of matter!
• Click Here

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References

• Garrett, G. (2004). Solids, Liquids, and Gases.
  New York, NY Scholastic Inc.
• http//thegreatwaterodyssey.com/images/soliqgas.gi
  f
• http//www.abpischools.org.uk/resources/solids-liq
  uids-gases/slg2.asp
• http//www.iit.edu/smile/ph9101.html
• http//www.apqj64.dsl.pipex.com/sfa/slg.htm
• http//www.btinternet.com/n.j.f/Y7science/resourc
  es/draganddrop/slgdragdrop.htm