1. UNIT 3 – TRANSFORMATIONS OF MATTER
PHYSICAL CHANGES
CHEMICAL CHANGES
LAW OF CONSERVATION OF MASS
PURE SUBSTANCES & MIXTURES

2. PHYSICAL CHANGES
Physical change: A transformation which does not affect the particles of a substance
The particles of the substance are the same. It is only the appearance of the substance which changes.
Ex. The water is always formed of water particles in the solid state (ice) , liquid ( water glass) or gas ( water vapor)
The physical changes are reversible. The substance may return to its initial state. Ex. The ice becomes liquid water when it melts

3. PHYSICAL CHANGES State changes of matter are physical changes
The changes of state of matter include:
Fusion (melting) solid to liquid
Freezing liquid to solid
Evaporation (boiling) liquid to gas
Condensation gas to liquid
Sublimation solid to gas
Deposition (solidification) gas to solid

4. PHYSICAL CHANGES: Reversable Transformations

5. PHYSICAL CHANGES: THE PARTICLE THEORY
The particle theory can help us understand the state changes.
Scientists use the particle theory to explain the structure of matter:
1 -Any substance is made of small particles.
2 - A substance is composed of same or different particle.
3 - There is space between the particles.
4 - The particles are always moving –
These movements are more or less rapid
depending on the temperature of the
substance.
5 - The particles of a substance
attract ( pull ) or repel ( repulsion )
one another - The strength depends
on the type of particles

6. PHYSICAL CHANGES: THE PARTICLE THEORY
Take a solid ( A)
The particles can only vibrate. When the solid is heated , the temperature increases because the particles vibrate more and stronger and faster.

7. PHYSICAL CHANGES: THE PARTICLE THEORY
The melting point (B)
The particles will vibrate so strongly that the links between them will turn The solid at its melting point and gradually turns into liquid.
The plateau in the graph is called the melting bearing.

8. PHYSICAL CHANGES: THE PARTICLE THEORY
The substance has now become a liquid ( C)
The particles can move slightly.
When heating the liquid , the particles will move more freely and more quickly

9. PHYSICAL CHANGES: THE PARTICLE THEORY
The boiling point (D)
The particles are moving so fast and so hard that the links between them will break.
The liquid reaches its boiling point and becomes gas.
The plateau in the graph is called the boiling stage

10. PHYSICAL CHANGES: THE PARTICLE THEORY
The substance has now become a gas ( E)
The particles rapidly disperse in all directions

11. CHEMICAL CHANGES: Radical Transformations
Chemical change: a transformation in which new substances are formed with their own properties.
Ex. Burning paper –
Ash and carbon dioxide are formed.
The paper is white, but the ash is gray.
The paper is solid, but the carbon dioxide is a gas. Can not recombine the ash and the carbon dioxide to form again the paper (non-reversible)

12. CHEMICAL CHANGES: Radical Transformations
4 clues that allow us to conclude that there was a chemical change:
Formation of a gas Formation of The production Change of
a residue of heat of light colour
Ex. - Baking bread Stalagmites & Fireworks Rust
Stalactites

13. LAW OF CONSERVATION OF MASS nothing is lost – nothing is created
Antoine Laurent Lavoisier,
a French scientist of the 18th century,
performed many experiments
on the transformations of matter
Lavoisier saw that the mass of
substances that are transformed is
always equal to the mass of the
substances that come out of the transformation.
He called this phenomenon:
The Law of Conservation of Mass – “Nothing is lost, nothing is created, everything is transformed.”

14. LAW OF CONSERVATION OF MASS nothing is lost – nothing is created
From melting ice (physical change) to liquid.
1 - Put ice in a closed container and take the weight of the container.
2 - Heat the ice on a hot plate.
3 - Take the mass of container with liquid water.
The mass remains the same before and after transformation.

15. LAW OF CONSERVATION OF MASS nothing is lost – nothing is created

16. PURE SUBSTANCES & MIXTURES
Pure substance: Contains only one kind of particle.
Ex. The salt, sugar, distilled water.
Mixture: Contains at least two kinds of particles.
Ex. The air, the sand at the beach, distilled water , etc.

17. PURE SUBSTANCES & MIXTURES
DISTILLED WATER (H₂O)
MIXTURE
SALT WATER (H₂O + NaCl)

18. MIXTURES – HETEROGENOUS or HOMOGENOUS
MATTER
PURE SUBSTANCES
MIXTURES
HOMOGENOUS
HETEROGENOUS
Contains only one type of particle.
Ex. Water, iron, Salt
Composed of atleast 2 types of particles
Properties are uniform
To the naked eye it looks like only ONE substance
Ex. Salt water, Loonie
Composed of atleast 2 types of particles
Properties are not uniform
To the naked eye you can tell that there are different substances
Ex. Smog, Twoonie

19. MIXTURES – HETEROGENOUS or HOMOGENOUS
Homogeneous mixture (solution):
A mixture in which one can not distinguish the different kinds of particles.
Ex. The air (Air is a mixture of gases, but you can not distinguish gases from each other )
- It looks like a pure substance.
Heterogeneous mixture : a mixture in which one can distinguish the different kinds of particles.
Ex. Smog ( The pollutants in the air are visible as gray cloud)

20. MIXTURES – HETEROGENOUS or HOMOGENOUS

21. MIXTURES – HETEROGENOUS or HOMOGENOUS
In a Solution (homogeneous mixture) as sugared water, the solute particles are uniformly distributed among the particles of the solvent.
Solute: The part of a mixture which is dissolved (ex. sugar). You can have several solutes.
Solvent: The part of a mixture that dissolves other substances (ex. water). There is only a solvent in a solution.

22. MIXTURES – HETEROGENOUS or HOMOGENOUS
SOLUTION
HOMOGENOUS
MIXTURE
SALT
(SOLUTE)
WATER
(SOLVENT)
SALT WATER
(SOLUTION)

23. MIXTURES – HETEROGENOUS or HOMOGENOUS
SALT PARTICLE
(solute)
WATER PARTICLE
(solvent)

24. MIXTURES – HETEROGENOUS or HOMOGENOUS
Salt & Water
MIXTURE
Sugar & Water
MIXTURE
Copper Sulfate
& Water
MIXTURE
Sand & Water
MIXTURE
Mud & Water
HOMOGENOUS
HOMOGENOUS
HOMOGENOUS
HETEROGENOUS
HETEROGENOUS

25. MIXTURES – HETEROGENOUS or HOMOGENOUS
Dissolution:
When two or more substances are mixed to form a solution.
The solvent dissolves the solute.
Ex. Hot Chocolate – (Solvent) Hot water dissolves (Solutes) Chocolate Powder, Milk, Marshmallows, Whipped Cream.

26. SEPERATION OF MIXTURES
Some techniques used for the separation of mixtures include:
1 – Sedimentation
2 – Decanting
3 – Filtration
4 – Distillation

27. SEPERATION OF MIXTURES SEDIMENTATION
After some time, the particles of a heterogeneous mixture will separate. The heavier particles settle to the bottom of the container where they form a sediment
Ex. Muddy water - The solids (heavier) settles to the bottom of the beaker and form a sediment.

28. SEPERATION OF MIXTURES SEDIMENTATION
Sedimentation technique
takes time
Ex. Orange juice - The pulp settles to the bottom of the container.
Ex. Salad Dressing - The vineger and oil separates and particles settle to the bottom of the container.

29. SEPERATION OF MIXTURES DECANTATION
Decanting:
Often used after sedimentation.
Decanting separates the layers of a heterogeneous mixture in various containers.
Ex. Muddy water - We can pour the water into another container leaving the sediment in the original container.

30. SEPERATION OF MIXTURES DECANTATION
A GLASS ROD
A SEPARATORY FUNNEL

31. SEPERATION OF MIXTURES FILTRATION
Used to separate the different substances of a heterogeneous mixture. It can replace sedimentation and decanting. During filtration, a mixture is passed through a filter paper which is perforated with many small holes. The paper retains the larger particles (the residue) and the hole let in the smaller (filtrate).
Ex. Coffee machines – keeps the grinds out and lets the water seep through into the cup

32. SEPERATION OF MIXTURES FILTRATION
Ex. Muddy water - Water (filtrate) will pass through the holes of the filter paper and the solid parts (the residue) will remain in the filter paper

33. SEPERATION OF MIXTURES DISTILLATION
Filtration can separate the different substances a homogeneous mixture ( solution ) using their boiling points.
Ex. The salt water - We start with warm salt water. When the temperature reached 100 ° C , water boils and is converted into steam. In the tube called the condenser, the steam cools and returns to the liquid state (condensation). Liquid water ( distillate ) accumulates in the beaker and there remains only the salt (the residue) in the flask.

34. SEPERATION OF MIXTURES DISTILLATION
BOILING POINTS:
WATER 100 °C
SALT 1,413 °C