What’s
That
Matter?
What’s that Matter?
Overview
Students will be able to define matter and explore how to classify matter around
them. Students will also be able to describe the motion of molecules in the
different states of matter and explore how the molecules motion change when
matter changes. Music, measurement, inquiry, models, literature strategies, and
alternative assessment provide the basis for development of various concepts.
National Science Education Standards:
As a result of activities in grades k-4, all students should develop
Content Standard A: Science as Inquiry
Abilities necessary to do scientific inquiry - asking simple questions about objects,
organisms and events in the environment, plan and conduct investigations using simple
equipment and tools to collect data and extend senses, use data to give an explanation to
observations, and communicate their ideas and results to others.
Content Standard B: Physical Science
Give students a chance to increase their understanding of the characteristics of objects
and materials that they encounter daily. Through the observation, manipulation, and
classification of common objects children will develop the understanding that Objects have
many observable properties, including size, weight, shape, color, temperature, and the ability
to react with other substances. Those properties can be measured using tools, such as rulers,
balances, and thermometers. They will also gain an understanding that matter can exist in
different states--solid, liquid, and gas. Some common materials, such as water, can be changed
from one state to another by heating or cooling.
Louisiana Benchmarks/GLE#
Science Inquiry
1.
Ask questions about objects and events in the environment
2.
3.
Pose questions that can be answered by using students’ own observations, scientific
knowledge, and testable scientific investigations
Use observations to design and conduct simple investigations or experiments to answer
testable questions
4. Predict and anticipate possible outcomes
6. Use a variety of methods and materials and multiple trials to investigate ideas (observe,
measure, accurately record data)
7. Use five senses to describe observations
8. Measure and record length, temperature, mass, volume, and area in both metric system
and U.S. system units
9. Select and use developmentally appropriate equipment and tools (e.g., magnifying
lenses, microscopes, graduated cylinders) and units of measurement to observe and
collect data
10. Express data in a variety of ways by constructing illustrations, graphs, charts, tables,
concept maps, and oral and written explanations as appropriate
12. Use a variety of appropriate formats to describe procedures and to express ideas about
demonstrations or experiments (e.g., drawings, journals, reports, presentations,
exhibitions, portfolios)
13. Identify and use appropriate safety procedures and equipment when conducting
investigations (e.g., gloves, goggles, hair ties)
15. Distinguish between what is known and what is unknown in scientific investigations
18. Base explanations and logical inferences on scientific knowledge, observations, and
scientific evidence.
20. Determine whether further investigations are needed to draw valid conclusions
21. Use evidence from previous investigations to ask additional questions and to initiate
further explorations
Physical Science
3rd Grade
18. Compare and classify objects on properties determined through experimentation
19. Select the appropriate metric system and U.S. system tools for measuring length, width,
temperature, volume, and mass
22. Investigate and explain conditions under which matter changes physical states: heating,
freezing, evaporating, condensing, boiling
4th Grade
24. Illustrate how heating/cooling affects the motion of small particles in different phases of
matter
What is Matter?
Probe
Purpose:
The purpose of this assessment probe is to elicit students’ ideas of what matter is. The probe
is designed to determine whether students recognize forms of matter and can distinguish
between things that are considered to be matter and things that are not. The probe helps
reveal what characteristics students use to decide if something is considered to be matter.
Explanation:
Items on the list considered to be matter are rocks, baby powder, milk, air, dust, cells, atoms,
smoke, salt, planets, steam, rotten applies, water, bacteria, oxygen, and stars.
Responses to fire may vary depending on how the student thinks of fire. If you considered the
gases given off by the fire the gases are matter. But the fire itself is not matter. Fire emits
heat and light which are forms of energy.
Items not considered matter are any forms of energy, forces, waves, and emotions.
All matter is made up of particles (atoms and molecules); has weight and mass; takes up space
(has volume); and exists in the forms of solid, liquid, gas, or plasma. In order to be considered
matter, an object, material, or substance must meet these characteristics.
Instructional considerations:
By the end of elementary grades, students frequently encounter the word matter in various
topes such as states of matter, properties of matter, and changes in matter. This is the time
when students develop an understanding that matter exists as a solid, liquid, or gas and has
properties that can be observed and measured, even with matter they cannot see, such as
gases. Students develop a beginning notion of “stuff” as matter by examining the materials
that make up objects. Energy is a more abstract idea at this stage. The probe is useful in
determining what elementary student’s initial ideas are about what constitutes matter and
what criteria they use. It is especially helpful to determine if they recognize gases as something
that fits with their conception of matter. You can also use this probe to help the student
revaluate their initial understanding and revise the definition of matter as new concepts are
developed.
What Is Matter?
Listed below is a list of things that are considered matter and things that are not
considered matter. Put an X next to each of the things that you consider to be
matter.
___ rocks
___ Mars
___ baby powder
___ Jupiter
___ milk
___ steam
___air
___ rotten apples
___ light
___ heat
___dust
___ sound waves
___ love
___ water
___cells
___ bacteria
___ atoms
___ oxygen
___ fire
___ stars
___ smoke
___ gravity
___ salt
___ magnetic force
Explain your thinking. Describe the “rule” or reason you used to decide whether
something is or is not matter.
Uncovering Student Ideas in Science
What is Matter?
By Pam Dillie
(adapt to the tune of “Three Blind Mice”)
What is matter?
What is matter?
A solid, liquid, or gas.
A solid, liquid, or gas.
It takes up space and it weighs something, too.
It’s everywhere – that includes me and you.
Did you ever think such a thing could be true?
That is matter.
That is matter.
States of Matter
Observations of the properties of the states of matter
Getting Started:
1. Decide what objectives you want to address.
2. Determine which objects you will like for the students to explore (make
sure it is different solids, liquids, and gas).
3. Set up different stations or you can demonstrate the different properties
of the objects at your desk.
4. Copy student handouts.
Materials:
For Each station you will need a solid, liquid, and a gas.
Station 1: wood block, cooking oil in small cup, balloon( one for each student in
class), balance scale
Station 2: soda, marble, balloon filled with air (just enough air to be able to
squeeze the balloon)
Station 3: 3 syringes: one filled with sand, one filled with air, and one filled with
rubbing alcohol
Station 4: rock, colored water, and picture of smoke particles
Procedure:
1. Assign groups to go to each station. Have the students practice walking
through the carousel.
2. Explain the procedure for each station.
3. Start the carousel. Let the students know when to switch to next station.
4. After each student has filled in their chart. Hand out the second sheet to
the groups to form definitions for a liquid, solid, and gas.
5. Have each group make a poster of their definitions and present to the
class.
6. Discussion of solid, liquid, gases will follow the activity.
** draw pictures, show motion of the molecules, bb model of states
http://www.chem.purdue.edu/gchelp/atoms/states.html
Station 1
Physical Properties
Use your five senses and measuring skills to make observations
about the physical properties of the following objects: wood
block, cooking oil, and air.
1. What color is the block and cooking oil?
2. Air is all around you, what color is air?
3. How do the objects feel to your touch?
a. Carefully rub your finger across the block.
b. Dip your finger into the oil and rub it on top of your
hand.
c. Wave your hand back and forth.
4. Use the balance scale and determine if the object has a
mass.
5. Does the object take up space (has volume)?
** For air: blow up a balloon. If the balloon gets bigger
then the air takes up space.
Station 2
Does the object’s shape change?
Follow the instructions below to determine if the following
objects shape change when placed in different containers.
marble, soda, air
Marble
1. Place the marble into the first container (labeled 1).
2. Now dump the marble into the second container(labeled 2).
3. Dump the marble onto the tray.
Soda
1. Pour the soda into the first container (labeled soda 1).
2. Now pour the soda into the second container (labeled soda 2).
3. Pour the soda back into the beginning cup.
What did you observe about the shape of the object in the
beaker compared to the graduated cylinder?
Did the objects expand to fill the containers?
Did the objects flow (pour) easily from container to
container?
The balloon is filled with air. Squeeze the balloon and make
observations. Try to picture what the air is doing inside of the balloon.
Did the air inside the balloon change shape?
Station 3
Can the object’s particles be pushed closer
together (Compressed)?
Follow the instructions below to determine if the objects can
be compressed.
1. Observe the Syringes. One is filled with rubbing alcohol, one
filled with air, and one filled with sand.
2. Carefully and lightly push the syringe downward (compressing)
the object.
Which objects’ particles could be compressed together?
Station 4
Can the object’s Volume change?
Follow the instructions below to determine if the following
objects shape change when placed in different containers.
Rock, colored water, picture of smoke
Rock
1. Fill the beaker to the 25 ml mark with the clear water.
2. Carefully place the rock into the beaker.
** take notice to where the level of water is located now. The
change in volume of water is the volume of the rock.
3. Repeat the above steps using the graduated cylinder.
Colored Water
1. Pour water into the beaker. Write the volume.
2. Now pour the water into the graduated cylinder. Write the volume.
3. Pour the water back into the first cup.
Did the objects volume change?
Make observations from the pictures of the different containers filled
with smoke particles.
** Each dot represents a smoke particle.
** notice the number of dots- no smoke added or taken away.
Did the smoke change its volume?
Smoke was poured from container 1 to container 2. Notice
that the number of particles didn’t change only the size of the
container.
Container 1
Container 2
States of Matter
(Student Sheet)
Wood
Block
Cooking
oil
Air
Marble
Soda
Smoke
Sand
Rubbing
Alcohol
Rock
Water
Yes
Yes
Can be
compressed
Changes
Volume
Can be Poured
(flows)
Changes
Shape
Has volume
Has Mass
Feels
like
color
Object
Paste this chart into your journal notebook before
conducting investigation.
States of Matter Examples
(Student Sheet)
Assume that all solids have the same properties, all liquids
have the same properties, and all gases have the same
properties.
Solid
Wood
Clay ball
Liquid
Cooking oil
Soda
Sand
rubbing alcohol
Rock
Water
Gas
Air
smoke
Discussion
Give a Reason why all of these objects are considered to be
examples of matter.
With the data collected, make a chart of your choice
discussing the properties of a solid, liquid, and gas.
Oobleck
Overview
This activity allows for the integration of Language Art skills
into a science lesson. The investigation of the Oobleck
properties can be done as an alternative assessment for
states of matter.
Getting Started:
1. Obtain a copy of Bartholomew and the Oobleck.
2. Prepare a Language Arts lesson centered around the book if you choose to
integrate subject Areas ( Partner up with a Language Arts teacher if you only
teach Science and Social Studies)
3. Make copies of the student sheet.
4. If you are using this activity as an alternative assessment; create a rubric
4. Make the Oobleck.
How to Make Oobleck (makes 3 bowls)
1. Put two tablespoons of corn flour into a container.
2. Place green food coloring into one cup of water.
3. Slowly pour the water into a container or bowl, stirring the mixture at
the same time.
4. Add more cornstarch if needed to get the correct consistency
5. Cover the bowl to prevent the Oobleck from drying out.
Procedure:
1. Review the properties of solids and liquids.
2. Read: Bartholomew and the Oobleck by Dr. Seuss and have the students
complete desired comprehension skills.
3. Tell students they will be able to play with their own Oobleck and determine
its state of matter.
Safety Notes:
Monitor the students to prevent Oobleck from being thrown around the
classroom. You may also have the students wear aprons to prevent spills on
their clothes.
Teacher Notes:
Make sure to cover the students’ desk with plenty of wax paper, Oobleck can be
extremely messy. You may consider doing this activity outside.
Oobleck
(Student Sheet)
Use the scientific method and observations to
determine Oobleck’s state of matter.
Focus Question (Problem):
What state of matter is OObleck?
Prediction (Hypothesis):
I think Oobleck is a _________.
Procedure:
Perform each of the following tests. Write what you see the Oobleck doing
(observation) for each task then determine whether it acted as a solid or a liquid
(infer which state of matter properties the Oobleck possess).
1. Pick up the Oobleck with a spoon.
2. Pour some of the Oobleck into another bowl.
3. Use a spoon to scoop out the Oobleck and place it on the paper.
4. Flatten the Oobleck like a pancake.
5. Hit the Oobleck with your hand.
6. Slowly poke the Oobleck with your finger.
7. Quickly poke the Oobleck with your finger.
8. Use a spoon to scoop out the Oobleck and roll it into a ball.
9. Bounce the Oobleck on the paper.
Conclusion:
Oobleck is a ___________ because _________________.
Phase Changes
Exploration of the changes in states of matter
Getting Started:
1. Gather materials.
2. Copy handout for students.
Materials: Per group
Baby food jar with lid
Ice
Strip of Foil
Salt in a small cup
Candle
Matches
Procedure:
1.
2.
3.
4.
Review Lab safety and states of matter with students.
Inform students they will observe different ways states of matter change.
Demonstrate the activity for the students
After activity discuss phase changes with students
** draw pictures, animations
http://www.harcourtschool.com/activity/states_of_matter
Safety:
Make sure that students are wearing safety goggles. Make sure to review lab
safety with fire with students. You may want to light the matches for your
students to prevent injury.
Phase Changes
(Student Sheet)
Directions:
Write the phase change name, follow the steps and write down your
observations.
Condensation:
1. Tape a strip of foil around a small jar.
2. Place several pieces of ice into the jar and close the lid.
3. Hold the jar by the lid and bottom and shake the jar making the ice touch
the sides of the jar.
4. Watch what forms on the foil and record your observations.
Freezing:
1. Pour pre-measured salt into the jar and close the lid.
2. Hold the jar by the lid and bottom and shake the jar making the ice touch
the sides of the jar.
3. Watch what forms on the foil and record your observations.
Melting:
1. Carefully remove the foil from the jar.
2. While holding the foil by the edges, watch what forms on the foil.
3. Watch what happens on the foil and record your observations.
Evaporation:
1. Carefully light your candle.
2. Using a clothespin, hold the foil over the flame of your candle.
3. Watch what happens on the foil and record your observations.
Analysis:
1. Which phase changes are caused by a loss of heat (exothermic)?
2. Which phase changes are caused by a gain of heat (endothermic)?
Kinetic Theory of Matter
(demonstration)
Overview:
This demonstration is to show students a visual of what happens to molecules of
liquid water as it turns into steam.
Materials:
Clothespin
Foil
Water
Candle
matches
Procedure:
1. Make a pocket with a piece of foil. Make sure the corners are sealed.
2. Place 10 to 15 drops of water into the corner of the pocket of foil.
3. Seal the pocket.
3. Place a clothespin on the opposite end of where the water droplets were
placed.
4. Light a candle.
5. Holding the clothespin, place foil over the candle. Be careful not to put the
foil into the flame.
Student Task:
Have the students write their observations and infer what is happening to the
water molecules.
Discussion: Questions and task for students
1. What phase change occurred?
2. How does this demonstration show the Kinetic theory of Matter?
Safety Notes:
Wear goggles when the candle is lit to prevent damage to your eyes.
Teacher Notes:
If you see steam coming from the corners or bubbles the pocket corners are not
sealed properly.
States of Matter
Poem
(author unknown)
Magic Water (H20)
When water freezes
Or water boils It gets a different name,
It turns to ice
It turns to steam But it's water just the
same!
EXTRA DEMONSTRATIONS
Physical or Chemical Changes
(Demonstration)
Boiling Water
Materials: water, beaker, hot plate
Task: 1. Fill beaker ¾ full with water.
2. Bring to boil.
Observe the boiling water and determine if the change is physical or chemical.
Physical Change: water is going from a liquid to a gas (state of matter change)
Alka Seltzer and Water
Materials: alka seltzer tablets, graduated cylinder, waste cup, beaker,
and water
Task: 1. Place 50 mil of water in a beaker.
2. Place ½ a tablet of alka seltzer into water.
3. Light a wood splint and place into beaker
(do not get splint wet)
Have students write their observations and predict whether it is a physical or
chemical change.
Chemical Change: bubbles formed-A new gas was produced (CO2) * made the
wood splint go out
Burning Candle
Materials: candle, match, waste container
Task: 1. Light the candle with a match.
Have students write their observations and predict whether it is a physical or
chemical change.
Physical Change: Candle wax went from solid to a liquid (melting) Chemical
Change: burning wick-light and heat were produced
Baking Soda and Vinegar
Materials: baking soda, spatula, vinegar, beaker, and waste container
Task: 1. Add 10 ml of vinegar into the beaker.
Have student smell the container.
2. Add a scoop of baking soda to the water.
3. Light a wood splint and place into the beaker
(do not get splint wet)
Have the students smell the container.
Have students write their observations and smell the container again. Have
them predict whether the change is chemical or physical.
Chemical Change: bubbles formed, new gas produced (splint went out), heard
fizzing and the smell changed
*** You can do this demonstration using a fish tank. Pour a lot of baking soda
into the tank, then pour the vinegar. Allow a few seconds to pass. Blow bubbles
into the tank.
Bubbles will float in the tank. (Review Density with the students)
NaCl and Water
Materials: salt, beaker, spatula, graduated cylinder, stirring rod, and
waste container
Task: 1. Add 20 ml of water to the beaker.
2. Add a small scoop of NaCl.
3. Stir with the glass rod.
Have students make observations and predict whether the change is physical or
chemical.
Physical Change: salt was only dissolved into the beaker. Properties of the
salt and the water are the same.
Cutting and Burning paper
Materials: scissors, paper, match, watch glass, and waste container
Task 1: Cutting
1. Cut the paper into 4 pieces.
2. Put the pieces on the watch glass.
3. Determine if the change is physical or chemical.
Task 2: Burning
1. Using a match, set the paper on fire.
2. Place match into waste container.
Have students make observations and predict whether it is a physical or
chemical change.
Cutting: physical change- still paper only smaller
Burning: chemical change- no longer paper turned into black ash, light, and
heat are produced.
Conservation of Matter
Overview
These activities are used to help students understand that the amount of matter
present in a substance will not change during physical and chemical changes.
During physical and chemical changes only the physical and chemical properties
change.
Getting Started
1. Make copies of handout
2. Gather materials
Materials:
Physical change activity: (per group)
Balance scale
Cookie
Paper towel
Probe
Chemical change activity: (demo)
Alka-seltzer tablet
Water
20 oz empty bottle with cap
Balance scale
Procedure:
1.
2.
3.
4.
Review physical changes.
Give the students the cookies crumble probe.
Have them plan their procedure.
Once you approve their procedure give the students a cookie and a
balance.
5.Discuss the student’s results.
6. Perform chemical change demonstrations.
7. Discuss student’s observations and conservation of mass during physical and
chemical changes.
Safety:
Make sure that you wear safety goggles when performing the demonstration.
Cookie Crumbles
Imagine you have a whole cookie. You break the
cookie into tiny pieces and crumbs. You weigh all
of the pieces and crumbs. How do you think the
weight of the whole cookie compares to the total
weight of all the cookie crumbs?
Circle the best (prediction) hypothesis.
a. The whole cookie weighs more than all of the cookie crumbs.
b. All of the cookie crumbs weigh more than the whole cookie.
c. The whole cookie and all of the cookie crumbs weigh the same.
How could you test your prediction (hypothesis)?
Results:
Fill in the data table below and perform the steps you have written above.
Conclusion:
I claim that ___________ ______________because_______________________.
Adapted from Uncovering Student Ideas in Science
Conservation of Mass with a Chemical Change
(demonstration)
Procedure:
1. Place water half full into the 20 oz. bottle.
2. Crack the Alka seltzer in half.
3. Weigh the bottle with water, Alka seltzer and the bottle’s cap on
a triple beam balance. Record the mass on the board.
4. Drop the alka seltzer into the bottle and quickly tighten the cap
on the bottle.
5. Make sure the reaction is complete.
6. Place the bottle onto the balance again. Record the mass on the
board.
Discuss with the students what they observed about the mass of the
system before and after the reaction took place.
** Open the bottle and allow the gas to escape. Weigh the bottle
again.
Discuss with the students why the mass of the system became lower.
(the gas that was produced during the reaction was released from
the system)
Background Information
Matter
Everything is made of matter. You, a toaster, a bowl, soup, steam, glass and
glowing gas are all made of matter. But what is matter exactly? Matter is anything
that has volume and mass. All matter is made of atoms and molecules.
Volume:
All matter takes up space. The amount of space taken up, or occupied, by
an object is known as the object’s volume. The sun has volume because it takes up
space at the center of our solar system. The Statue of Liberty, your fingernails, a
cloud all have volume. Because these things have volume, they cannot share the
same space at the same time. Even the tiniest speck of dust takes up space, and
there’s no way another speck of dust can fit into that space without somehow
bumping the first speck out of the way.
Mass:
Another characteristic of all matter is mass. Mass is the amount of matter
that something is made of. For example, the Earth is made of a very large amount of
matter and therefore has a large mass. A peanut is made of a much smaller amount
of matter and thus has a smaller mass. Remember, even something as small a speck
of dust is made of matter and therefore has mass.
An object’s mass can be changed only by changing the amount of matter
in the object. Consider a bowling ball, its mass is constant because the amount of
matter in the bowling ball never changes (unless you use a sledgehammer to remove
a chunk of it!) Now consider a growing puppy. Its mass will change because it is still
gaining matter until it is a full grown dog.
Describing Matter
Knowing the properties of an object can help you determine the object’s
identity. You rely on physical properties all the time. For example, physical
properties help you determine whether your socks are clean (odor), whether you can
fill all your books into your backpack (volume), or whether your shirt matches your
pants (color). Physical property of matter can be observed or measured without
changing the identity of the matter. For example, you don’t have to change what the
apple is made of to see that it is red or to hold it in your hand.
Physical
Property
Density
More physical properties
Definition
Example
Mass per unit
volume
Thermal
Conductivity
The ability to
transfer thermal
energy from on area
to another
State
Physical form in
which a substance
exists, such as a
solid, liquid, gas, or
plasma
The ability to be
pounded into thin
sheets
Malleability
Ductility
Solubility
Boiling point
Freezing
point
The ability to be
drawn or pulled into
a wire
The ability to
dissolve in another
substance
Temperature at
which a substance
will start turning into
a gas
Temperature at
which a substance
will freeze
Lead is used to make
sinkers for fishing line
because lead is more
dense than water
Plastic foam is a poor
conductor, so hot
chocolate in a plastic
foam cup will not
burn your hand
Ice is water in its
solid state.
Aluminum can be
rolled or pounded
into sheets to make
foil.
Copper is often used
to make wiring.
Sugar dissolves in
water.
Water has a boiling
point of 100 o C
Water has a freezing
point of 0o C
Physical properties are not the only properties that describe matter. Chemical
properties describe a substance based on its ability to change into a new substance
with different properties. For example, a piece of wood can be burned to create new
substances (ash and smoke) with properties different from the original piece of
wood. Wood has the chemical property of flammability – the ability to burn.
More Chemical Properties
Chemical
Property
nonflammability
Reactivity with
oxygen
Reactivity to light
Definition
Example
Cannot burn
Reacts with oxygen
to make a new substance
Reacts with light to make a new
substance
nonreactive
Doesn’t react with a substance
Gold will not burn
Iron reacts with oxygen
to form rust
Reason why some
medicine bottles or
brown. Hydrogen
Peroxide has brown
bottle. It will turn into
water and oxygen gas
under light.
Neon gas doesn’t react
with other elements.
Iron doesn’t react with
oil.
Four States of Matter
The states of matter are physical forms in which a substance can exist. For
example, water commonly exists in there different states of matter: solid (ice), liquid
(water), and gas (steam).
Matter consists of tiny particles called atoms and molecules that are too small to
see without a powerful microscope. These atoms and molecules are always in
motion and are constantly bumping into one another. The state of matter of a
substance is determined by how fast the particles move and how strongly the
particles are attracted to one another.
Figure below demonstrates three of the states of matter- solid, liquid, and gasin terms of the speed and attraction of the particles.
Solids have definite shape and volume. The particles of a substance in a solid
are very close together. The attraction between them is stronger than the
attractions between the particles of the same substance in the liquid or gaseous
state. The atoms or molecules in a solid move, but not fast enough to overcome the
attraction between them. Each particle vibrates in place because it is locked in
position by the particles around it.
Liquids change shape but not volume. Liquids will take the shape of whatever
container it is put in. The atoms or molecules in liquids move fast enough to
overcome some of the attractions between them. The particles slide past each other
until the liquid takes the shape of its container. Even though liquids change shape,
they do not readily change volume. You know that a can of soda contains a certain
volume of liquid regardless of whether you pour it into a large container or a small
one.
Gases change both shape and volume. The atoms or molecules in a gas move
fast enough to break away completely form one another. Therefore, the particles of
a substance in the gaseous state have less attraction between them than particles of
the same substance in the solid or liquid state. In a gas, there is empty space
between particles. The amount of empty space in a gas can change. For example,
the helium in a metal cylinder consists of atoms that have been forced very close
together. As the helium fills the balloon, the atoms spread out, and the amount of
empty space in the gas increases.
Plasmas is the state of matter that does not have a definite shape or volume
and carries a charge. Scientists estimate that more than 99 % of the known matter in
the universe, including the sun and other stars, is made of plasma. It has some
properties that are quite different from the properties of gases. Plasmas conduct
electric current, and electric and magnetic fields affect plasmas. Natural plasmas are
found in lightning, fire, start, and incredible light show called the aurora borealis.
Artificial plasmas, found in fluorescent lights and plasma balls, are created by
passing electric charges through gases.
Physical Change of matter
A physical change is a change that affects on or more physical properties of a
substance. For example, if you break a piece of chalk in two, you change its physical
properties of size and shape. But no matter how many times you break it, chalk is
still chalk. The chemical properties of the chalk remain unchanged. Because
physical changes do not change the identity of substances, they are often easy to
undo.
Some examples of physical changes:
 Change in state of matter
 Cutting your hair
 Sanding a piece of wood
 Crushing an aluminum can
 Bending a paper clip
 Making a mixture (ie: oil and vinegar)
Changes in State (Physical Change)
A change of state is the conversion of a substance from one physical form to
another. All changes of state are physical changes.
During a change of state, the energy of a substance changes. The energy of a
substance is related to the motion of its particles. The molecules in the liquid water
move faster than the molecules in the ice. Therefore, the liquid water has more
energy than the ice.
If energy is added to a substance, its particles move faster. If energy is removed,
its particles move slower. The temperature of a substance is a measure of the speed
of its particles and therefore is a measure of its energy. For example, steam has a
higher temperature than liquid water. A transfer of energy, known as heat, causes
the temperature of a substance to change, which can lead to a change of state.
Melting is the change of state from a solid to a liquid. This is what happens
when an ice cube melts. The melting point of a substance is the temperature at
which the substance changes from a solid to a liquid. Melting points of substances
vary widely. For a solid to melt, particles must overcome some of their attractions
to each other. When a solid is at its melting point, any energy it absorbs increases
the motion of its atoms until they overcome the attractions that hold them in place.
Melting is an endothermic change because energy is absorbed by the substance as it
changes state.
Freezing is the change of state from a liquid to a solid. The temperature at
which liquid changes into a solid is its freezing point. Freezing is the reverse process
of melting, so freezing and melting occur at the same temperature. For a liquid to
freeze, the motion of its atoms or molecules must slow to the point where
attractions between them overcome their motion. If a liquid is at its freezing point,
removing more energy causes the particles to begin locking into place. Freezing is an
exothermic change because energy is removed from the substances it changes state.
Vaporization is simply the change of state from a liquid to a gas. It is an
endothermic change. Boiling is vaporization that occurs throughout a liquid.
The temperature at which a liquid boils is called its boiling point. Like the
melting point, the boiling point is a characteristic property of a substance.
Evaporation is vaporization that occurs at the surface of a liquid below its
boiling point. When you perspire, your body is cooled through the process of
evaporation. Perspiration is mostly water. Water absorbs energy from your
skin as it evaporates. You feel cooler because your body transfers energy to the
water. Evaporation also explains why water in a glass on a table disappears
after several days.
Atmospheric pressure will change the boiling point of liquids. Atmospheric
pressure is caused by the weight of the gases that make up the atmosphere. It
varies depending on where you are in relation to sea level. Atmospheric
pressure is lower at higher elevations. The higher you go above sea level, the
less air there is above you, the lower the atmospheric pressure. Liquids will boil
at a lower temperature.
Condensation is the change of state from a gas to a liquid. For a gas to become
a liquid, large numbers of atoms or molecules must clump together. Particles clump
together when that attraction between them overcomes their motion. For this to
occur, energy must be removed from the gas to slow the particles down. Therefore,
condensation is an exothermic change.
Sublimation is the change of state from a solid directly into a gas. Dry ice is
colder than ice, and it doesn’t melt into a puddle of liquid. It is often used to keep
food, medicine, and other materials cold without getting them wet. For a solid to
change directly into a gas, the atoms or molecules must move from being very tightly
packed to being very spread apart. The attractions between the particles must be
completely overcome. Because this requires the addition of energy, sublimation is
an endothermic change.
Deposition is the change of state from a gas directly into a solid. This is how
freezers get ice forming onto the sides. For a gas to change directly into a solid, the
atoms or molecules must move from being very spread apart to being very tightly
packed. The attractions between the particles must completely overcome their
motion. Because this requires the loss of energy, deposition is an exothermic
change.
Summarizing the changes of State
Direction
Endothermic
Example
or
Exothermic
Change in
State
Melting
Solid to Liquid
Endothermic
Freezing
Liquid to Solid
Exothermic
Vaporization
Liquid to Gas
Endothermic
Condensation
Gas to Liquid
Exothermic
Sublimation
Solid to Gas
Endothermic
Deposition
Gas to Solid
Exothermic
Ice melts into liquid water at
0oC
Liquid water freezes into ice at
0oC
Liquid water vaporizes into
steam at 1000C at sea level
Steam condenses into liquid
water at 1000C
Solid dry ice sublimes into a
gas at -78oC
Water vapor turns into ice in
the freezer
When most substance lose or absorb energy, one of two things happens to the
substance: its temperature changes or its state changes. When the temperature
rises the speed of the particles will change. But while a substance changes state, its
temperature does not change until the change of state is complete.
Vaporization
Condensation
100
Energy Added
Boiling Point
Temperature(oC)
Energy Added
Energy Added
0
Melting Point
Liquid
Energy Added
Energy Added
Solid
Melting
Freezing
Time
Gas
Chemical Change
A chemical change occurs when one or more substances are changed into
entirely new substances with different properties. This is different than a chemical
property. A chemical change is the actual process in which a substance changes the
chemical property describes how a substance could behave. You can observe
chemical properties only when a chemical change might occur.
There are always clues to signal whether a chemical change is occurring. The
more clues produced the greater the chance the changes are chemical.
Clues to Chemical Changes
 Bubbles producing a new gas (ie: Carbon Dioxide gas, Hydrogen gas,
Oxygen gas)
 Change in a substance’s smell
 Noise produced
 Heat produced
 Light produced
Conservation of Mass:
Regardless of the type of change physical or chemical, the amount of matter
present will not change only the physical or chemical properties of the substance will
change.