PPT Notes

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Physical Science
What is matter?
Matter: anything that has mass and takes up space
 Matter is made up of extremely tiny particles called
atoms and molecules.
 Atoms and molecules make up the three common
states of matter on Earth
1) solids
2) Liquids
3) gases
Solids
Solids: Has a definite shape and a definite volume
 They do not take the shape of their container because
they do not have enough energy
 Particles of solids are tightly packed, vibrating about a
fixed position.
Examples: Wood, rock, plastic
Liquids
Liquids: Has a definite volume and does not keep its
shape
 Takes the shape of the container because the particles
have enough energy to move out of their fixed position
by not enough energy to move apart.
 Particles of liquids are tightly packed, but are far
enough apart to slide over one another.
Examples: water, alcohol, vegetable oil
Water properties activity
Procedure
1. Use a dropper to gently squeeze out one drop of water but try
not to let the drop fall completely out of the dropper. See how
far you can make the drop hang off the end of the dropper
without the drop falling.
2. Place 4 or 5 drops of water together on the wax paper to
make a medium-size drop.
3. Gently tilt the wax paper in different directions so that the
drop moves.
4. Use a popsicle stick to slowly move your drop around the wax
paper. Try using your popsicle stick to separate your drop into
two.
5. Use your popsicle stick to move the two drops near each
other. Then move one drop so that the two drops touch.
Viscosity
Viscosity: a liquid's resistance to flow
 the slower a liquid flows, the higher the viscosity
 The viscosity results from the strength of the attraction
between the particles
 Viscosity increase as the liquid becomes colder
Example: Honey has higher viscosity than water
Surface Tension
 Surface Tension: The uneven forces acting on the
particles on the surface of a liquid.
 attractive forces causes particles to pull together and
resist pulling apart.
 Ex. Water spider moving on the surface of a pond
Water has surface tension
 Water molecules are held together by
hydrogen bonds
Water balloon video
www.middleschoolchemistry.com/multimedia/chapter1/lesson1
#water_balloon
Why do you think the water keeps its shape the
moment the balloon is popped?
water holds together pretty well because the
water molecules are attracted to each other.
Imagine a drop of water hanging from your
finger. How is this similar to the water staying
together after the balloon is popped?
water molecules are very attracted to each
other by hydrogen bonds
Play water drop
unite 1.1
Surface Tension
lab
Gases
Gases: Does not have a definite shape or volume
 Move at high speed in all directions
 Particles of gases are very far apart and move freely
 Can expand or be compressed
Examples: Carbon Dioxide, Oxygen, Helium
Changes of state
 Temperature: The average kinetic energy of the
individual particles
 Heat: The movement of thermal energy from a
substance at a higher temperature to one at a lower
temperature.
 Heat Loss: When a substance looses heat and energy;
results in a change of state of matter
 Heat Gain: When a substance gains heat and energy;
results in a change of state of matter
Affects of temperature on solid
matter
Ring and Ball demo
Materials for the Demonstration
• Ball and ring designed specifically for this demonstration]
• Bunsen burner for heating the ball
• Room-temperature water (to cool the ball)
Demo :
www.middleschoolchemistry.com/multimedia/chapter1/less
on4#heating_cooling_metal_ball
 Draw a model of the atoms in the metal ball at room-
temperature and after it has been heated. Use circles and motion
lines to show the speed and spacing of the atoms in the roomtemperature ball. Include captions like “atoms faster and further
apart” or “atoms slower and closer together” to describe your
drawings
Affects of temperature on solid
matter
 In a solid, the atoms are very attracted to one another.




The atoms vibrate but stay in fixed positions because
of their strong attractions for one another.
Heating a solid increases the motion of the atoms.
An increase in the motion of the atoms competes with
the attraction between atoms and causes them to
move a little further apart.
Cooling a solid decreases the motion of the atoms.
A decrease in the motion of the atoms allows the
attractions between atoms to bring them a little closer
together.
Affects of temperature on liquid
matter
Is the speed of water molecules different in hot and
cold water?
Materials
 Hot water in a clear plastic cup
 Cold water in a clear plastic cup
 Food coloring (yellow and blue)
 4 droppers
1) Describe what the colors looked like and how they moved and
mixed in the cold water.
In the cold water, the yellow and blue colors drifted and slowly
swirled and spread a bit but were in streaks. The colors didn’t mix
very much.
2) Describe what the colors looked like and how they moved and
mixed in the hot water.
In the hot water, the colors spread more quickly and mixed
together more than in the cold water. The water turned greener in
the hot water than it did in the cold water.
3) What does the speed of the mixing colors tell you about the
speed of the molecules in hot and cold water?
Since the colors moved faster in the hot water, it means that the
water molecules in the hot water move faster than the molecules in
cold water.
www.middleschoolchemistry.com/multimedia/chapter1/lesson2#hea
ting_and_cooling
Affects of temperature on gaseous
matter
Heating and cooling affect
balloon
Materials
 Balloon
 Water bottle
 plastic container filled with
water
 ice and hot water
Molecules of gas:
Why does the balloon inflate when the bottle is placed in
the hot water?
because the molecules that make up the air inside the bottle
moved faster. These molecules hit the inside of the bottle and
balloon harder and more often. They pushed against the
balloon hard enough that it was able to overcome the outside
air pressure and made the balloon grow.
2) Why does the balloon deflate when the bottle is placed in
the cold water?
because the molecules that make up the air inside the bottle
moved slower. These molecules hit the inside of the bottle
and balloon less often and with less force. The outside air
pressure pushed harder on the outside of the balloon than
the molecules pushed from the inside so the balloon got
smaller.
1)
Heat Transfer
Conduction
Convection
 Materials: Solids and liquids
 Materials: Gases and
 Heat Flow: Direct contact
Liquids
 Heat Flow: Warm air rises,
cool air sinks (convection
currents). Indirect contact
 Example: Air Currents
between heat source and
matter
 Examples:
 Metal spoon in water-heats
fast
 Wooden spoon in waterheats slow
Heat Transfer
Radiation
 Materials: Travels through a
vacuum (absence of air)
 Heat Flow: Travels in waves
 Example: Sunlight travels
through space (through a
vacuum) then energy is
absorbed by earths
atmosphere (air) and the
objects on earth
Which one are you seeing?
Heat Transfer
Radiation
 Materials: Travels through a
vacuum (absence of air)
 Heat Flow: Travels in waves
 Example: Sunlight travels
through space (through a
vacuum) then energy is
absorbed by earths
atmosphere (air) and the
objects on earth
Which one are you seeing?
A
B
C
Phase Change
 When matter changes from one form to another
 Phase change depends on the heat/energy of
particles
 When a change of state occurs, energy is either lost to
other matter, or gained by other matter. Energy can
be transferred from one object to another but it can
NEVER be destroyed (The law of conservation of
energy)
Type of phase
change
Melting
Freezing
Boiling
Vaporization
Evaporation
Condensation
Sublimation
Deposition
Change
Heat (+ or -)
Type of phase
change
Change
Melting
Solid to Liquid
Freezing
Boiling
Vaporization
Evaporation
Condensation
Sublimation
Deposition
Heat (+ or -)
+
Type of phase
change
Change
Melting
Solid to Liquid
+
Freezing
Liquid to Solid
-
Boiling
Vaporization
Evaporation
Condensation
Sublimation
Deposition
Heat (+ or -)
Type of phase
change
Change
Melting
Solid to Liquid
+
Freezing
Liquid to Solid
-
Boiling
Liquid to Gas
+
Vaporization
Evaporation
Condensation
Sublimation
Deposition
Heat (+ or -)
Type of phase
change
Change
Melting
Solid to Liquid
+
Freezing
Liquid to Solid
-
Boiling
Liquid to Gas
+
Vaporization
Liquid to Gas
+
Evaporation
Condensation
Sublimation
Deposition
Heat (+ or -)
Type of phase
change
Change
Melting
Solid to Liquid
+
Freezing
Liquid to Solid
-
Boiling
Liquid to Gas
+
Vaporization
Liquid to Gas
+
Evaporation
Liquid to Gas
+
Condensation
Sublimation
Deposition
Heat (+ or -)
Type of phase
change
Change
Melting
Solid to Liquid
+
Freezing
Liquid to Solid
-
Boiling
Liquid to Gas
+
Vaporization
Liquid to Gas
+
Evaporation
Liquid to Gas
+
Condensation
Gas to Liquid
-
Sublimation
Deposition
Heat (+ or -)
Type of phase
change
Change
Melting
Solid to Liquid
+
Freezing
Liquid to Solid
-
Boiling
Liquid to Gas
+
Vaporization
Liquid to Gas
+
Evaporation
Liquid to Gas
+
Condensation
Gas to Liquid
-
Sublimation
Solid to Gas
+
Deposition
Heat (+ or -)
Type of phase
change
Change
Heat (+ or -)
Melting
Solid to Liquid
+
Freezing
Liquid to Solid
-
Boiling
Liquid to Gas
+
Vaporization
Liquid to Gas
+
Evaporation
Liquid to Gas
+
Condensation
Gas to Liquid
-
Sublimation
Solid to Gas
+
Deposition
Gas to Solid
-
Phase change
Vaporizes
Evaporates
Water
 Freezing point: 0°C
 Melting point: ___ 0°C _
 Boiling point: _____100 °C______
 Absolute Zero -The lowest possible
temperature; when molecules can no
longer move. The basis for the Kelvin scale
(0 Kelvin means all motion/energy stops).
But what happens if you raise the
temperature to super-high levels…
between
1000°C and 1,000,000,000°C ?
Will everything
just be a gas?
STATES OF MATTER
PLASMA
 A plasma is an
ionized gas (remove
electron)
 A plasma is a very
good conductor of
electricity and is
affected by
magnetic fields.
 Plasmas, like gases • Plasma is the
have an indefinite
common state
shape and an
of matter
indefinite volume.
STATES OF MATTER
SOLID
Tightly packed, in
a regular pattern
Vibrate, but do not
move from place to
place
LIQUID
Close together
with no regular
arrangement.
Vibrate, move
about, and slide
past each other
GAS
Well separated
with no regular
arrangement.
Vibrate and move
freely at high
speeds
PLASMA
Has no definite
volume or shape
and is composed of
electrical charged
particles
Some places where plasmas are found…
1. Flames
2. Lightning
3. Aurora (Northern Lights)
The Sun is an example of a star in its
plasma state
Lab Groups
 When you go to your station, you will need everything
(we will be going back to notes while you are there)
 Be as neat as possible at your station. The first demo
lab we will do is the evaporation lab.
Changes of state
Evaporation:
 Does adding heat (energy) or making something cold
increase evaporation?
Do evaporation lab demo
 Materials for each group
 3 quart-size zip-closing plastic storage bags
 Hot water (about 50 °C)
 Room-temperature water
 Cold ice water
 3 squares of brown paper towel
 3 droppers
Evaporation
 Evaporation occurs when molecules in a liquid gain
enough energy that they overcome attractions from
other molecules and break away to become a gas.
 Adding energy increases the rate of evaporation.
Ex. Adding heat
Evaporation video
http://www.middleschoolchemistry.com/multimedia/chapter2/lesso
n2
Water molecules
http://www.middleschoolchemistry.com/multimedia/chapter2/lesso
n2
Condensation
Question to investigate
Does making water vapor colder increase the rate of
condensation?
Materials for the demonstration
 2 tall rimmed clear plastic cups
 2 tall smaller-rimmed clear plastic cups
 Room-temperature water
 Hot water (50 °C)
 Ice cubes
 Gallon-size zip-closing plastic bag
Condensation on a cup video
http://www.middleschoolchemistry.com/multimedia/chapter2/lesson3
Condensation
 Condensation is the process in which molecules of a
gas slow down, come together, and form a liquid.
 When gas molecules transfer their energy to
something cooler, they slow down and their attractions
cause them to bond to become a liquid.
Condensation video:
http://www.middleschoolchemistry.com/multimedia/chapter2/lesso
n3
Making water vapor colder increases the rate of
condensation.
 Increasing the concentration of water vapor in the air
increases the rate of condensation.
Condensation
Show the animation Evaporation & Condensation
http://www.middleschoolchemistry.com/multimedia/cha
pter2/lesson3
Examples:
 Water vapor on a cup
 Fog
 Moisture on a car window
 Dew
 Clouds
 The fog that comes from your mouth on a cold day
Freezing
 Freezing is the process that causes a substance to
change from a liquid to a solid.
 Freezing occurs when the molecules of a liquid slow
down enough that their attractions cause them to
arrange themselves into fixed positions as a solid.
Show the movie Ice Can
http://www.middleschoolchemistry.com/multimedia/cha
pter2/lesson4
Show the movie Ice Bomb
http://www.middleschoolchemistry.com/multimedia/ch
apter2/lesson4
Melting
 Melting is a process that causes a substance to change
from a solid to a liquid.
 Melting occurs when the molecules of a solid speed up
enough that the motion overcomes the attractions so
that the molecules can move past each other as a
liquid.
Show students the video Ice Melting on Different Surfaces.
www.middleschoolchemistry.com/multimedia/chapter2/lesson5#ice_melti
ng_on_different_surfaces
Show the animation Melting Ice.
www.middleschoolchemistry.com/multimedia/chapter2/lesson5#melting_i
ce
Ice versus Water
 Ice is an orderly crystal structure
 Water molecules in ice vibrate but don’t move past
each other.
Ice
Water
Ice versus Water
 As the temperature increases water molecules begin to
vibrate more.
 Eventually their movement overcomes their attractions
and they can no longer stay in their orderly crystal
structure.
Ice versus Water
 As the ice melts, the orderly arrangement collapses
and the water molecules move past each other and
actually get closer together as liquid water.
Ice on a can
http://www.middleschoolchemistry.com/multimedia/chapter2/lesson4
Sublimation
Does all ice melt the same??
 Dry ice is frozen carbon dioxide gas. Carbon dioxide gas must be
very cold in order to become a solid (about –78 °C or –109 °F).
Video-Dry Ice
http://www.middleschoolchemistry.com/multimedia/chapter2/lesso
n5
Sublimation occurs when molecules of a solid move fast enough to
overcome the attractions from other molecules and become a
gas.
Video-Ice bomb
http://www.middleschoolchemistry.com/multimedia/chapter2/lesson5
Since frozen carbon dioxide never becomes a liquid under normal
pressure, it is called dry ice.
Deposition
Gas turns into a solid
Ex. Frost
Video of a snowflake forming at
http://www.its.caltech.edu/~atomic/snowcrystals/movies
/movies.htm
Download