States of Matter
A Kinetic Experience
Kinetic Theory of Matter
Also known as the Molecular theory of matter:
• All matter is made of molecules and
atoms that act like tiny particles
• Molecules are always in motion. The
higher the temperature, the faster the
particles move
• At the same temperature, heavier
particles move slower than lighter
particles.
Solid, Liquid, Gas
Balls in Box Demo
• Small vibrations = Solid
• More Energy Added in the form of
heat energy, bouncing inside box =
Liquid
• Even More Energy Added in the form
of heat energy, balls falling out of box
= Gas (evaporation) Heavier
molecules evaporate at a slower rate.
• Putting the balls back into the box =
Condensation
Why metal balls inside some of
the tennis balls?
• Heavier molecules take more energy
to evaporate.
• Lighter molecules evaporate more
readily.
• Video – Kinetic Molecular Theory
Watch as the
water
molecules
gain enough
kinetic energy
to evaporate.
How does thermal energy affect the
state of a substance?
• Thermal Energy interactive Video –
Investigate at home
• Video molecules in motion
Amazing Ice Melting Blocks
• http://www.youtube.com/watch?v=v
qDbMEdLiCs&feature=c4-overviewvl&list=PL772556F1EFC4D01C
Amazing Ice Melting Blocks
• Oh, my the way, The “cold” block and the
“warm” block are both the same
temperature, namely room temperature.
• What did you notice?
1. Things at the same temperature can
feel as though they are at different
temperatures.
2. The ice on the two blocks melts at
extremely different rates, in a way that
is completely unexpected.
Amazing Ice Melting Blocks
What’s happening?
The “cold” Block
The “warm” block
• Made of Al
• High heat conductivity
• Feels cold because it is
rapidly conducting
heat from your hand
• Cools your hand much
more than expected
so your brain tells you
the block is cold.
• Made of Plastic Foam
• Poor conductor of heat.
(Due to gas bubbles in it)
• Feels warm because heat
is conducted more slowly
from your hand
• Warmer to your hand
than what is expected so
your brain tells you the
block is warm.
Amazing Ice Melting Blocks
What’s happening?
So if they are both at room temperature
why did one melt the ice faster?
 Ice must have heat energy transferred
to it before it will melt.
• The high heat conductivity of the Al
block allows it to conduct heat rapidly
to the ice- resulting in a rapid melting.
Temperature
• Temperature is the average
kinetic energy of the atoms
(or molecules) in a system.
Temperature measures how
“hot” something is.
Temperature Scales
• Fahrenheit English system
– Water freezes at 32 degrees Fahrenheit and boils
at 212 degrees.
• Celsius modern system
– freezing point of water 0 degrees Celsius, and the
boiling point 100 degrees Celsius.
• Kelvin A scale that is based on energy content .
– At zero Kelvin (absolute zero) all molecular motion
stops.
– Scientists have figured out a way to get a
temperature only a few billionths of a degree
above absolute zero.
5 States of Matter
• Elements and compounds can move from
one phase to another when specific
physical conditions are present.
• When the temperature of a system goes
up, the matter in the system becomes more
excited and active.
• As the temperature rises, matter moves to
a more active state.
5 States of Matter
•
•
•
•
•
•
Bose-Einstein Condensates (BEC)
Solids
Liquids
Gases
Plasmas
Each of these states is also known as a
phase.
What is a Condensate?
Think Condensation
• Condensation happens when several gas
molecules come together and form a liquid. The
molecules get denser or packed closer together.
• It all happens because of a loss of energy. Gases
are really excited atoms. When they lose energy,
they slow down and begin to collect.
• Water (H2O) vapor in the form of steam condenses
on the lid of your pot when you boil water. It cools
on the metal and becomes a liquid again. You
would then have a condensate.
What is a solid?
• Solids have a
– definite shape
– definite volume.
– Molecules are tightly packed
– Cannot move freely, can only vibrate
– Molecules stay fairly still.
– Energy and temperature are very low
Types of Solid
Crystalline Solids- Repeating pattern ex.
Ghost crystals, crystals in rocks, salt, rock
candy
Amorphous Solids- - Non-repeating
pattern ex. Wax, play dough, hand putty,
peanut butter, gum, clay
DRAW A SOLID.
What is a liquid?
Liquids have
• no definite shape, take shape of container in which it is held
• Definite or fixed volume.
• Molecules are closely packed
• Molecules vibrate and slide around one another easily.
• Energy and temperature, in comparison to a solid, are
higher
• The force of attraction between these particles is called
intermolecular forces. These force cause liquid particles to
be fairly close together, thus raising the density of a liquid
compared to a gas.
A misconception that molecules do not touch in a liquid.
Demo Examples:
Water in different sized containers.
Water in syringe
Water in baggie.
DRAW A LIQUID.
Solid/LiquidCheck-Up
1. Describe particle motion in a solid.
2. Describe particle motion in a liquid.
3. What are two different types of
solids? Give 1 example of each.
4. What is a common misconception
about liquids?
What is a Gas?
• Gases have indefinite and unstable shape
• No definite volume, volume determined by container
• Molecules can vibrate, slide, spin, and bounce off of one
another.
• Molecules are far apart and can move around quickly.
• Energy and temperature are the higher than those of both
solids and liquids
• Gases diffuse (The movement of particles from a region of
high concentration to a region of low concentration) .
• Heat will increase the rate of diffusion.
Examples:
Perfume
“tooting your little horn”
Lysol
Ammonia
Did you know that
Gases were also
called fluids?
Why?
DRAW A GAS.
Vapor vs. Gas
•
Vapor and gas mean the same thing.
•
The word vapor is used to describe
gases that are usually found as liquids.
•
Good examples are water (H2O) or
mercury (Hg). Water and mercury are
liquids at room temperature, so they
get the vapor title when they are in a
gaseous phase.
•
Compounds like carbon dioxide (CO2)
are usually gases at room temperature,
so scientists will rarely talk about
carbon dioxide vapor.
Water Vapor from a
geyser
Compressed Gases
With very little pressure, gas molecules can
be compressed.
Examples
– compressed air in a spray bottle
– When you feel the carbon dioxide
rush out of a can of soda.
• These gas were forced into a smaller
space so the gas escapes the first chance
it gets.
• The gas molecules move from an area of
high pressure to one of low pressure.
What is plasma?
•
•
•
Charged particles --Ionized
Gas-- a cloud of protons,
neutrons and electrons where
all the electrons have come
loose from the atoms
This is an extreme gas! Strikes
the other atoms so forcefully
it knocks off an electron!
These gases
– vibrate,
– Slam into one another
causing bright gases,
– lots of heat
– lots of energy.
• Hotter than gas. A plasma
occurs when the
temperature is between
1000 degrees C and
1,000,000,000 degrees C
Neon
Signs
Plasma Examples
Our Sun,
the core
of stars
Lightning
Plasma TV
Aurora
Borealis
plasma balls
Plasma Cutters
Human
Christmas
Tree
DRAW PLASMA.
Plasma the 4th State of
Matter
Gas/Plasma Check-Up
1.
2.
3.
4.
Describe particle motion in a gas.
Describe particle motion in plasma.
What is another name for plasma?
How is plasma formed?
A Phase Change
• A "phase" describes a physical state
of matter.
• The key word to notice is physical.
– If energy is added (like increasing the
temperature) or if energy is taken away
(like freezing something), you have
created a physical change.
A Phase Change
• A compound or element can move from one phase
to another, but still be the same substance.
• It may require extreme temperatures or extreme
pressures, but it can be done.
Melting or Fusion
• The change of state from solid to
liquid
• Melting Point - the temperature at
which matter changes from solid to
liquid, (e.g. The melting point of
water from ice to liquid water is 0 °C)
Vaporization
• Matter changing from a liquid to a
gas.
• Energy is added to the system.
• Boiling Point - the temperature at
which matter changes from a liquid to
a gas, (e.g. The boiling point of water
from liquid water to steam is 100 °C)
Demo –
Super Heated SteamWater molecules move so fast that are able to burn paper.
Boiling Pressure and
Temperature
Water Phase Change using a Vacuum Pump
Vaporization, Boiling,
Evaporation
Boiling vs. Evaporation
Boiling
Evaporation
Vaporization
Occurs at or above the boiling
temperature.
At temperatures below the
boiling temperature at a
given pressure.
There are two types of
vaporization: evaporation
and boiling.
Boiling, as opposed to
evaporation, occurs below the
surface.
Usually occurs on the
surface.
Vaporization involves very
quickly heating a compound
above its boiling point
causing it to become a gas all
at once
Involves the formation of bubbles
of the vapor throughout the bulk
of the liquid
Takes place only at the
surface of the liquid --- No
Bubbles
Demo –
Boiling FlaskHand boiler
Water in vacuum pump
Butane in BaggieButane’s boiling point is so low
that the heat from your body will
make butane reach it’s boiling
point.
Water on your skin on a hot
day
Alcohol rub
Super Heated Steam
Evaporation
How does evaporation differ
from vaporization?
Boiling vs. Evaporation
Pressure and Phase Change
• If lowering the temperature won’t get
a liquid to change to a solid just apply
pressure.
• By applying pressure you are
“pushing” the molecules together.
• Example
– To change Liquid Nitrogen (N2) to a solid pressure must
be applied.
– Demo – Fire Syringe
Temperature and Pressure
Click to run
• Phet- Use this interactive model to
learn more about how temperature
and pressure are related.
Demo
Drinking Bird
Hand Boiler
Evaporation Demonstrations
Alcohol TimingAlcohol evaporated quicker than water
because molecules are lighter.
Flaming FlaskMystery substance is less dense than water
and burns until all molecules are
evaporated.
Flaming Money –
Alcohol is evaporated when heat energy is
added. Money is dry.
Large Water Bottle
Evaporative Cooling
• When high energy particles escape a liquid, the
average energy of the remaining particles is less so
the liquid cools.
• The cool liquid then cools the surface on which it is
resting.
Examples:
- Joggers cooling down as their sweaty clothes dry
out
– Water cools down a roof on hot summer day
– A wet cloth is placed on your forehead when you
have a fever
Review Questions
1. How does temperature effect state
change?
2. Why does alcohol evaporate more
quickly than water?
3. When butane changes from a liquid to
a gas is energy released or absorbed?
4. Why did the flaming money remain
unharmed when it was caught on fire?
Sublimation
Matter changing from a
solid directly to a gas.
(skipping the liquid
phase)
Examples:
Dry Ice (frozen Carbon
Dioxide)
Snow in parking lot that
does not melt
Mothballs in closet
Old ice cubes in freezer
Condensation
• Matter changing
from a gas to a
liquid.
Examples:
Glass of ice water
Bathroom mirror
after shower
Hot breath on bus
window
Dew on grass.
Freezing or Solidification
• the change of state from liquid to
solid
Water is the only known substance that expands as
it freezes. Most Substances contract.
Deposition
• Matter changing from a
gas directly to a solid.
(Skipping the liquid
phase)
Examples:
Frost on glass- Water
vapor becoming a solid
Demo – Mothballs on a
hotplate making crystals.
Thermal Expansion
• Thermal expansion is the tendency of a
matter to change in volume in response
to a change in temperature.
Examples:
Demo - Ball and Ring
Demo- Bimetallic Strip (Brass and Iron)
Sidewalk cracking
Doorway
Cracks in house foundation
Heating and Cooling Curves
• Heating Curve Link
Hotplate Activity
Heat of Fusion
Heat of Fusion
Heat of Vaporization
Heat of Vaporization
Particles in Motion- Heating
Curve of Water
• http://www.dlt.ncssm.edu/tiger/Flash
/phase/HeatingCurve.html