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Y9 Science: Matter, Mixing and Separating
At the end of this unit you will be able to……………
1 Describe the macroscopic properties of the states of
matter and explain why solids, liquids and gases are used
for particular jobs in terms of their macroscopic
properties.
2 Measure density and compare the density of different
materials
3 Name the changes of state and relate these changes to the
loss or gain of energy
4 Use a particle model to explain the properties of solids,
liquids and gases, and discuss what happens to the
particles when a substance changes state
5 Explain diffusion in terms of particle behaviour
6 Explain expansion and contraction of a substance in
terms of particle behaviour
7 Find by experiment whether substances are soluble or
insoluble; distinguish between solutes and solvents; create
saturated solutions and explain the effect of temperature
on solubility
8 Describe the difference between a solution and a
suspension
Habits of Mind development
9 Separate suspensions by the following techniques, and
explain what happens: decanting, centrifugation and
filtration (distinguish between a residue and a filtrate)
10 Separate solutions by the following techniques to re-gain
either the solvent or the solute, and explain what happens:
evaporation and distillation
11 Use and explain a variety of techniques for separating
solids to include: magnetism, gravity
12 Separate different solutes from a solution by
chromatography and explain what happens
13 Evaluate the different separation methods and identify a
suitable method to separate various mixtures
14 Be able to use each word from the list below in a sentence
(that makes sense)
By the end of the unit you should have developed your ability to....
15 Question and Pose Problems
16 Applying past knowledge to new situations
17 Create, Imagine and Innovate
18 Remaining open to continuous learning
19 Thinking Interdependently
20 Persisting
You should be able to define these words and write intelligent
sentences using them:
Matter
Mass
Volume
States of matter
Density
Changes of state
Melting
Evaporation
Boiling
Solidify
Sublimation
Reverse
sublimation
Particles
Particle theory
Theory
Expand
Boiling point
Diffusion
Contract
Conductor (of
heat)
Insulator (of heat)
Properties
Pure substances
Mixtures
Solution
Solute
Solvent
Soluble
Insoluble
Suspension
Dilute
Concentrated
Saturated
Solubility
Decanting
Centrifuge
Filtering
Residue
Filtrate
Distillation
Chromatography
Activity 1.1 Compressing solids, liquids and gases.
1. Carry out the following activities and record your
observations below: Put your thumb over the end of the
syringe and push the plunger in.
Syringe with air Syringe with water syringe with sand
2. Write inferences for each of the syringes:
Air filled:
Water filled:
Sand filled:
Activity 1.2 Describing Matter
1. List the properties of solids liquids and gases in the table
(think about particle proximity, particle movement and shape
and volume)
Solid Liquid Gas
2. Name the two states of matter that can change shape –
explain why they can.
3. Explain why you can pour sand even though it is a solid.
4. Explain how you can prove that you cannot change the
volume of a solid or liquid.
5. Why do gases take the shape of their container?
Activity 1.4 Heating Ice
Your teacher will give you some crushed ice, a conical flask and a
balloon. Set up a Bunsen and tripod with gauze as shown below.
OBSERVATIONS
Before heating During heating During cooling
Take photographs at each stage.
Inferences (explanations using scientific knowledge).
Record your observations as you heat
flask over the Bunsen and then as you
allow it to cool (lift it off the tripod and
onto the heat proof mat. Then write an
explanation about what is happening in
the flask and to the ice/water particles
and give reasons for your observations.
Activity 1.4 Describing phase changes
1. Write the phase change names beside:
Solid → liquid
Liquid → solid
Liquid → gas
Gas → liquid
Gas → solid
Solid → gas
2. Fill in the gaps in the diagram
Liquid
Gas Solid Gas Liquid
3. Complete the table:
Phase change Heat energy in or out?
Melting
Subliming
Freezing
Evaporating
Reverse subliming
condensing
4. Complete the table:
Phase change situation
Frost forms on grass
Ice-cream becomes liquid
Fruit juice is made into ice-blocks
Water forms on the mirror in the
bathroom
Dry ice ‘smokes’
The kettle boils
5. Explain why water forms on the outside of a glass of
iced drink.
6. Explain why your glasses ‘steam up’ when you open the
oven door?
7. Decide whether each statement is true or false.
Write corrected statements for the false one (underneath
the false statement)
A Solids have a fixed shape. T/F
B Matter is anything that exists.
C Liquids and solids can be poured.
D Particles in gases move fast and are not attracted
to each-other.
E Liquids take the shape of their container as the
particles are not attracted to each-other.
F The particles in solids can move around each-
other
G Gases and liquids have a fixed volume.
H As the temperature increases the particles in all
states move more.
I Solids have a fixed shape.
J Matter is anything that exists.
8. Complete the following sentences:
a. In solids the particles ______ because the particles cannot
_______.
b. Diffusion occurs in ______ and ______ because the
particles are moving.
c. Solids have a fixed shape because…….
d. Write a paragraph about the information in the diagram:
Activity 2.1 Measuring Density
Your teacher will give some objects and ask you to find their
density. You will need to find the mass of each object first and
then their volumes. You will need to exactly measure a volume of
water and then put the object into the water to find its volume
(volume with object – volume without object). Calculate the
density by dividing the mass of the object by the volume of the
object. Complete the table below:
Object Mass
(g)
Initial
volume
(mL)
Final
volume
(mL)
Volume
Of object
(mL)
Density
(g/mL)
Answer the questions below:
1. What is the unit of density?
2. Which object has the highest density?
3. Which object/s sink in water?
4. Water has a density of 1.0 g/mL which can also be written as
1.0 gmL-1. Why do objects sink in water?
Activity 2.2 Density calculation practice
Calculate the densities of the objects below and answer the
questions:
Object Object
mass (g)
Volume
of object
(mL)
Density
of
object
(g/mL)
A 27 2
B 15 4
C 30 12
D 65 12
E 17 1
F 83 13
G 19 2
Questions:
1. Which object has the highest density?
2. Which object has the lowest density?
3. List the objects from highest to lowest density:
4. Which objects will float on water? (density of water is 1.0
g/mL)
5. Why are aluminium cans able to float on water when the
density of aluminium is 2.7 g/mL?
6. Fill in the table:
Volume of
water in
millilitres (mL)
Volume of
water in L
(litres)
Mass of
water in g
Mass of
water in kg
(kilograms)
6
75
120
500
2000
5500
10 000
Activity 2.3 Density in different liquids
Measure out 10 mL of water and 10 mL of glycerine in separate
measuring cylinders. Slowly pour the glycerine down the side of
the measuring cylinder containing water so that the glycerine
flows gently in. Place a small piece of Perspex in the top of the
measuring cylinder and record your observations.
Observations:
Inferences:
Activity 3.1 Observing diffusion in air/gases
Your teacher will use some kind of spray or perfume to
demonstrate diffusion. Record your observations and then explain
using particle theory why the smell eventually reaches the back of
the room.
Questions:
1. Would you expect smells to move faster on a hot or cold
day? Explain your answer.
2. Why do smells move faster around a room when there is a
fan going?
Activity 3.2 Observing diffusion in liquids
Your teacher will demonstrate diffusion in water using purple
potassium permanganate crystals and a straw in three different
beakers. One will be iced water, another will have room
temperature water from the tap and the last will have boiled water
in it.
Questions:
1. Record your observations: (take a photograph too)
Iced water Room temp water Boiling water
2. Why did your teacher use a straw to put the crystals down
the bottom of the beaker in each case?
3. In which beaker was the diffusion fastest? Explain using
particle theory why this is so.
4. What makes the purple colour spread?
Activity 4.2 Observing expansion and contraction in gases
Your teacher will demonstrate expansion of gases using a balloon,
some hot water and a tape measure.
Record your observations: (take a photograph)
Questions:
1. Why did the balloon expand?
2. Why do gases take the shape of their container?
3. Why did the balloon have to be held down in the water?
Activity 4.2 Observing expansion and contraction in liquids
1. Your teacher will demonstrate the expansion of water (with
purple colouring) in a round bottomed flask. He/she will
mark the water level on the neck of the flask before placing
the flask into a container with hot water.
Record your observations: (take a photograph)
2. Your teacher will demonstrate placing a gas jar with hot
purple water upside down on top of another gas jar with cold
clear water in it and sliding out the lid (carefully).
Record your observations: (take a photograph)
Questions:
1. Explain why the water level in the round bottomed flask
changed in terms of the energy of the water molecules and
what they are doing.
2. Explain your observations for the gas jar demonstration in
terms of the temperature and density of each liquid.
Activity 4.3 Observing expansion and contraction in solids
1. Your teacher will provide a ball and ring apparatus and
explain how to use it. You will be heating either the ball or
the ring strongly in a Bunsen flame and then trying to fit the
ball through the ring. After you have done this you will cool
the ball or ring under the tap and try again.
2. Your teacher will give you a bimetallic strip and ask you to
heat it in the Bunsen flame. After heating cool it under a tap.
Observations:
Before heating After heating
Observations:
Before heating After heating
Questions:
1. What caused the change you observed with the ball and
chain?
2. Did the particles themselves expand?
3. Describe the motion of the particles before and after heating.
4. Why did the bimetallic strip bend?
5. What could bimetallic strips be useful for?
Activity 5.1 Describing mixtures
A Pure Substance is made of just one kind of atom or molecule,
so it can be an element or a compound. You can write the
formula for a compound as it always has the same molecules.
A mixture is not a pure substance is as it is made of more than
one type or atom or molecule.
When you put salt into water you make a mixture. When a solid
dissolves in a liquid you get a solution. A solution is made of a
solute dissolved in a solvent.
Questions:
1. Write definitions for the words in bold above.
2. Label the boxes above with ‘element’, ‘compound’ or
‘mixture’.
3. Sometime solvents are used to dissolve solutes when they are
stains on clothes. Use the information in the table to decide
on what solvent you would use to remove ballpoint ink from
your shirt.
Solvent Nylon shirt Ball pen ink
Water insoluble insoluble
Toluene insoluble soluble
Methanol soluble soluble
Kerosene insoluble insoluble
4. Fill in the table:
5. A solution can be described as concentrated or dilute
depending on how much solute has been added. Circle the
most concentrated solution in each of the following
examples:
a. Coffee with one sugar/coffee with 3 sugars
b. Milo made with 4 spoonful/milo made with 1 spoonful
c. Dark tea/pale tea
6. Fill in the gaps:
a. Solutions that cannot dissolve any more solute are called
_________________.
b. If a mixture settles after standing a while it is a
_____________.
c. You can dissolve more ____________ in hot water than
you can in ___________ water.
d. If a mixture is not dissolved and the particles can settle
out we say that the particles are ________________ in
the liquid.
e. Two liquids that can be mixed are said to be
_______________.
Solute Solvent Solution
Sea water
Milo
Raro powder Raro drink
Washing powder
Black coffee
Flavouring Milk
f. Why two liquid form two layers when mixed we say
that they are _________________.
g. A solution with little solute dissolved is said to be
___________ whereas a solution with a lot of solute
dissolved is said to be _________________.
7. How do you tell the difference between a solution and a
suspension?
Activity 5.2 Observing solubility
Your teacher will give you some solids to try dissolving in water
and ethanol. Use small amounts and correct technique for mixing
(no finger over the top and shaking). Your teacher may give you
test tubes with stoppers.
Fill in the table with your observations:
Solid Soluble in
water?
Observations
Flour
Sugar
Salt
Copper sulfate
Coffee
Solid Soluble in
ethanol?
Observations
Flour
Sugar
Salt
Copper sulfate
Coffee
Questions:
1. What solids were soluble in water?
2. What solids are soluble in ethanol?
3. What happened to the insoluble solids? Describe them.
Activity 5.3 Observing and describing suspensions
Blow through a straw into limewater and it goes cloudy. It is
cloudy because the white solid calcium carbonate is being made.
Calcium carbonate is not soluble (it does not dissolve) it is just
suspended in the water. If you leave it long enough you will see a
white solid on the bottom. The same happens to muddy water.
Practical: Your teacher will give you some muddy water. In your
group decide how you could separate the mud from the water.
Check with your teacher and then use the equipment provided to
separate the mud from the water. Insert a photograph showing
your method below:
Questions:
1. Did your method work? Explain your answer.
2. How could you describe the mixture or mud and water?
3. Describe another method of separating this mixture.
Activity 6.1 Separating Techniques: Decanting
Questions:
1. How effective was this method for separating sand and
water? Explain your answer.
2. What other mixtures could you separate using this method?
3. Draw a scientific diagram of decanting and photograph it.
Insert it here:
You will be given a shaken mixture of sand
and water. Using a stirring rod across the top
of a beaker, carefully pour the water off the
sand.
Activity 6.2 Separating Techniques: Filtration
Questions:
1. How effective was this method for separating chalk
dust/silt/mud and water? Explain.
2. What other mixtures could you separate using this method?
3. Would it be possible to filter sea water (to get the salt out)
using this method? Explain your answer.
4. Draw a scientific diagram of filtration (label filtrate and
residue) and photograph it. Insert it here:
You will be given a mixture of sawdust and water or water with silt/mud in it. Using a filter funnel and filter paper filter the mixture. You teacher will show you how to fold the filter paper.
Activity 6.3 Separating Techniques: Centrifuging
Questions:
1. Explain in your own words how a centrifuge works.
2. A washing machine is a centrifuge. Explain this statement.
3. Centrifuges only work on a special type of mixture. Explain
with examples what this means.
A centrifuge is used to speed up sedimentation in suspensions.
Your teacher will show you a centrifuge and explain how it works.
Activity 6.4 Separating Techniques:
Evaporation or Crystalisation
Questions:
1. How effective was this method for separating the solution?
Explain your answer.
2. Where has the liquid gone?
3. Take a photograph of your evaporating dish after you have
finished heating and insert it here:
4. What other mixtures could you separate using this method?
5. Draw a scientific diagram of evaporating and photograph it.
Insert it here:
You will be given a copper sulfate solution.
Set up a Bunsen burner on a baseboard and
heat a small volume of the solution over the
Bunsen using an evaporating dish, tripod
(and gauze if needed). WEAR SAFTEY
GLASSES. *It may spit towards the end
Activity 6.5 Separating Techniques: Distillation
Questions:
1. How effective was this method for separating the solution?
Explain your answer.
2. Where has the liquid gone?
3. Where has the solute gone?
4. Explain why the distillate is not purple.
5. Take a photograph of your distillate after you have finished
heating and insert it here:
6. What other mixtures could you separate using this method?
7. Draw a scientific diagram of distillation and photograph it.
Insert it here:
You will be given a potassium
permanganate solution. Set up a Bunsen
burner on a baseboard and heat a small
volume of the solution over the Bunsen
using a conical flask with delivery tube,
tripod and gauze. Catch the distillate in
another conical flask as shown in the
photo. WEAR SAFETY GLASSES.
Activity 6.6 Separating Techniques: Magnetic Separation
Questions:
1. Describe how magnetic separation is used in industry.
2. What metals are magnetic?
Activity 6.7 Separating Techniques: Chromatography
Questions:
1. Take a photograph of your chromatography starting and
finishing. Insert the photographs here:
2. What colour did you start with and what colours did you see
at the end?
3. What other mixtures could you separate using this method?
Use a magnet to separate the sand from the
iron filings but be very careful not to get
iron filings on the magnet (or you will
spend your lunchtime picking them off!)
Follow your teacher’s instructions and set
up your chromatography as shown in the
photo.
Activity 6.8 Separating Techniques: Revision Questions
1. Name the separation techniques that you would use to
separate these mixtures:
a. blood
b. peas in water
c. sea water to get the salt
d. sea water to get the water
e. colours in beetroot juice
f. chalk dust in water
g. iron nails from sawdust
2. Describe how you would separate a mixture of salt, sand and
sawdust. Explain all steps and name what is separated in
each step.
3. Describe how you could get fresh water from seawater if you
were on a deserted island. You have access to fire.
4. Use the following words to fill in the blanks:
Gases, kinetic, constant, liquids, solids, close,
temperature, average, volume, expand, past, particles,
tightly, vibrate, fast, faster, energy.
_________________ in all substances are in
_________________ motion. In _______________ the
particles are _______________ packed together and can only
________________. In _________________ the particles are
close together but can move _____________ each other. In
____________ the particles are far apart and move very
_________.
When you heat a substance the particles gain ____________
energy and moves ______________ or vibrate more
vigorously.
_________________ is a measure of the ______________
kinetic ____________. Heating solids (especially metal)
causes them to ____________ because the particles tend to
vibrate a lot. In gases the particles move faster and further
apart when heated so their ______________ increases.
Solutions: Use these words to fill the gaps: solvent, evaporate,
dilute, miscible, immiscible, solute, saturated, concentrated,
unsaturated.
A solution is a (usually solid) dissolved in a
(liquid)
A solution is when not much solute is dissolved and
when a lot of solute is dissolved.
A solution cannot dissolve any more solute but an
solution can dissolve more solute.
Two liquids are if they mix and if they form layers
If you want the solute back you need to the liquid to
crystallise the solute.
Suspensions : Use these words for the gaps: centrifuge, faster,
sediment, filter, suspension.
An insoluble solid shaken in a liquid forms a . It
looks cloudy or milky at first, but as you watch it clears and the
particles settle to the bottom forming a . So a
suspension does not dissolve and eventually settles.
Suspensions are not transparent (you cannot see through them)
A centrifuge helps suspensions settle
You can a suspension.
Chromatography and Evaporation : Use these words to fill in the
gaps: smallest, bigger, evaporation, chromatography.
The process called is used to separate
large and small molecules by running a solvent through a
mixture.
Colours in ink can be separated by chromatography. The
__
molecules travel the most and the molecules don’t.
The process of is heating a solution so that
the liquid evaporates leaving crystals
Activity 6.9 Heads and Tails
Match the heads with the correct tails by putting the correct
number in the first column.
COMPRESSIBLE 1 An explanation of what is happening
CONDENSATION 2 Becoming larger due particles vibrating
more
CONTRACTION 3 Becoming smaller on cooling
DENSITY 4 Mass divided by volume
DIFFUSION 5 Particles are able to be pushed closer
together
EVAPORATION 6 Phase change
EXPANSION 7 Phase change gas to liquid
FREEZING 8 Phase change gas to solid
GAS 9 Phase change liquid to gas
INFERENCE 10 Phase change liquid to solid
LIQUID 11 Phase change solid to gas
MASS 12 Stat of matter where particles are close
together but can move
MATTER 13 State of matter where particles are held
in position
MELTING 14 State of matter with particles far apart
and moving fast
OBSERVATION 15 Takes up space and has mass
REVERSE
SUBLIMATION
16 The amount of matter in an object.
Unit : kg
SOLID 17 What can be seen, heard, smelt, felt or
tasted
SUBLIMATION 18 When a substance spreads slowly
through a liquid or gas
Activity 6.10 Crossword
Matter Mixing and Separating Across
1 made of one type of molecule
7 crystallisation
9 made of one type of atom
10 what goes through the filter
13 two liquids can mix
14 liquids form two layers
15 evaporating and condensing Down
2 describes a solution that can dissolve more solute
3 a solution that cannot dissolve any more solute
4 in raro the solute is the ___________
5 solute + solvent mixed
6 in raro the solvent is _________
8 what is caught on the filter
11 what is mixed into the solvent
12 the liquid that the solute is dissolved in
Extension Extension activities
1. Explain what is happening to the particles where the graph is
red:
2. Fill in the Venn diagram:
Solid Gas
Liquid
3. Explain the phase changes in the diagram and explain how
you could use distillation to get fresh water from seawater.
4. Explain in detail how the particles behave as a metal rod is
heated and then cooled again:
5. What makes a bimetallic strip useful in electrical circuits?
6. Explain how this thermometer works:
7. Explain why power lines sag on hot days and are less saggy
on winter days.
8. Explain why diffusion occurs only in liquids and gases.
9. Label the hottest and coldest beakers below and explain what
causes the difference in diffusion rate.
10. In chromatography the colours move at different rates.
Explain what makes the colours spread out.
11. Explain how a vacuum cleaner works using the terms
filter, filtrate and residue.
12. Describe how you would separate a mixture of salt, sand
and sawdust. Explain all steps and name what is separated
in each step.