Unit 3: Phases of Matter

What is Matter?

• Matter means everything, anything that we can hold.

• All matter has MASS and takes up SPACE remember, mass is measured in grams

and space means it has volumeWhat is not matter?

Light –you can’t hold it in your hands! You can’t measure its mass

States of Matter

• There are three main forms of matter…on Earth• They are: solids, liquids, and gases• Each are defined by their physical properties• Matter can physically change and nothing new

is made…think water (ice, water, gas) we call this transition a phase change

• In the Universe though, there are 4 states of matter

Solids

• Have a defined shape and defined volume• Solids do not conform to containers…try to fit

a brick into a soda bottle• Additionally, they are the most difficult phase

of matter to penetrate (its really hard to push your finer through a brick)

• Solids are hard to penetrate because of the way their molecules are arranged

Solids• The molecules of solids come together in patterns

• Pattern layers provide strength • These molecules don’t move

much either –they hold tight• That’s not to say there isn’t

motion, there is! • Solids, all though still to us,

vibrate at a molecular level.• Review from Unit 2:

Absolute Zero = zero entropy = no molecular movement

Special type of Solid• Amorphous Solid• Any solid that acts like a liquid…it does not

have a crystal (pattern) structure• Examples include:

Plastic, glass and wax

Liquids

• Does NOT have a defined shape• Liquids take the shape of their container…you

can fill a bottle from the sink and the liquid takes the shape of the bottle!

• Liquids do have a defined volume, still takes up the same space…500mL = 500mL regardless of container

• Water (H2O) is the most common liquid

• Since liquids take the shape of their container, at a molecular level their molecules are free to move

• Liquid molecules are constantly moving.

• If liquids, say water, lose energy they become solids and if they gain energy they move further apart and become gasses.

Liquids

Special Property of Liquids

• Viscosity –the tendency of a liquid to resist flow

• High Viscosity = slow flowing (like glue or syrup)

• Low Viscosity = fast flowing (like water)

Gases

• Do NOT have a defined shape • Do not have a defined volume• Gasses fill whatever space is available (they

take the shape of their container)• We cannot determine how much volume they

have (unless we create that situation) --In other words how much Oxygen is occupying this room right now…?

• At a molecular level, gasses move freely (even more than liquids)

• Since they are so free to move they are very spread out.

• What is the most common gas…

AIR!!!

Gas

Air is made of…

• Nitrogen = 78% Oxygen = 21% Other (water vapor and CO2) = 1%

More review…in our galaxy gasses are compressed through gravity and make stars Speaking of stars…

The 4th State of Matter: Plasma

• Plasma is the most common phase of matter in the Universe

• Found in our Sun (which is a star)

• There are billions of stars in our galaxy alone

• The Sun is made of super hot gas and expels radiation (light and heat) through nuclear fusion…it turns Hydrogen into Helium

Summary

• 4 states of matter: Solids, liquids, gasses and plasma

• These states are defined by their physical properties (shape and volume)

• Energy plays a big role in the conversion from one state to another

• Since we define states by their physical properties its important to remember we are not making new matter just changing “shape”

Skipping a Phase

• Matter can skip a phase (normally it travels in a straight line)

Solid Liquid Gas Plasma

With enough energy, matter can skip a phase.Sublimation is when matter skips the liquid phase and goes from solid to liquid -Water and CO2 can do this