States of MatterStates of MatterStates of MatterStates of Matter

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Content Standards• Mc REL Standards

– Physical Sciences• Standard 8:Understands the structure

and properties of matter

What are we learning here?

We will•recall about the different states of matter•recall the molecular structure of different

states of matter.•think over and understand what makes them to behave the way they do.

What is matter?

Anything that occupies space and has a mass is called matter

States of matter• There are four states of matter

– Solids– Liquids– Gases– Plasmas (we are not going to discuss this here)

Stop & ThinkHow do you classify matter as Solids, liquids

or gases?

Two factors that distinguish them are

ShapeVolume

Let us analyze• Let us think about Solids

Look at the solids and identify their shapes by clicking the buttons

Cube

Cylinder

Cuboid

Cube

Cylinder

Cuboid

Cube

Cylinder

Cuboid

Click here if you are done

Great! You are right!

Get a Star

Go back to the questions

Oooooooops!

Try Again!

Go back to questions

Can solids change the shape on their own?

YES NO

Ooooops!

Oh No! They cannot change their

shape on their own!

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Do Solids have a definite shape?

Yes they do.

Now that you are clear about solids, Let us

take the case of liquids.

Liquids• I am pouring a liquid from one

container to another. What happens to its shape?

Changes

Do not change

I am sorry

• The shape of the liquid changes and it takes the shape of the container.

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Great! Now answer this!

Do liquids have a definite shape?

Click here for answer

No

• They don’t. They take the shape of the container.

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Gases• Can we say Oxygen is spherical in

shape & Carbon-di-oxide is cubical?

YES NO

No

They do not have a shape of their own.

Volume• Volume is the space occupied by

matter.

• Do Solids occupy space?

• Can they increase or decrease their space on their own?

YES NO

YES NO

Continue

You are right!

Continue

No! You are wrong!

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Volume• Let’s take the case

of Liquids• If I pour a liquid

from one container to another, Will the volume change?

YES NO

Ooooops!

No! If I pour 20 cc of water from one container to another, the 20 cc will remain the same and it will not change.

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Great! Let us take the case of Gases!

If I keep 20 cc of oxygen on a table in a room, will it remain there after sometime?

YES NO

I am sorry!

• No. It will not remain there after sometime. Gases spread around and they don’t stay at a place like solids or liquids.

Back again!

Great!Now answer these questions!

• Do Solids have definite volume?

• Do Liquids have definite volume?

• Do Gases have definite volume?

YES

YES

YES

NO

NO

NO

Continue

You are right!

Continue

I am sorry!

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Putting together• Solids have

– Definite shape and volume

• Liquids have– Definite volume but not shape

• Gases have– No shape or volume

Now let us look at the molecular structure of

solids

The molecules of solids are closely packed and are fixed. They cannot move freely but they can only vibrate about their mean positions.

Molecular Structure of Liquids

• In case of liquids, the molecules can move freely but within their volume.

Molecular Structure of Gases

• In Gases, the molecules are absolutely free and they can move anywhere.

ExtensionWhat makes the molecules of

Solids, liquids and gases behave the way they do?As an extension activity, go online

& check about Cohesion & Adhesion on the Internet.

Some useful links could be:

http://www.physlink.com/Education/AskExperts/Index.cfmAsk an expert -

http://www.topscience.org/co_adhesion.htmTop Science.org -

http://hyperphysics.phy-astr.gsu.edu/hbase/surten.html#c4Eduseek -