1. Physical Properties of Pure Substances
Intensive vs. Extensive

2. Essential Standard
6.P.2 Understand the structure, classifications and physical properties of matter.

3. Clarifying Objective
6.P .2.3 Compare the physical properties of pure substances that are independent of the amount of matter present including density, melting point, boiling point, and solubility to properties that are dependent on the amount of matter present to include volume, mass and weight.

4. Essential Question What is an INTENSIVE property of a pure substance?
What is an EXTNESIVE property of a pure substance?
What is the main difference between INTENSIVE & EXTENSIVE properties of pure substances?

5. Pure Substance
A Pure Substance is a sample of matter that has the same COMPOSITION & CHEMICAL PROPERTIES
All Elements on the Periodic Table & Water are pure substances

6. Periodic Table

7. Physical Properties
A physical property of a substance is a property that can be seen without changing the substance into another substance
Examples include…
Color
Luster (shiny)
Odor

8. Intensive Physical Properties
Intensive Physical Properties are those properties that no matter what size will ALWAYS BE THE SAME
Intensive Physical Properties include…
Solubility
Density
Melting Point
Boiling Point

9. Solubility Solubility is the ability of a substance to dissolve
If the pure substance cannot dissolve it is said to be insoluble
The faster a pure substance dissolves the more soluble it is

10. Solubility
Solubility is Intensive as it does not matter how much of the substance you have it will either dissolve or it won’t (INTENSIVE)
The speed of dissolving does not matter on how much of the substance you have it will still dissolve at the same speed

11. Solubility (Example)
If you stir a cup sugar in some water it disappears into the water
The sugar disappearing is the sugar DISOLVING making sugar soluble
It doesn’t matter if you put 2 cups of sugar into water it will still dissolve
KOOLAID

12. Density
Density is how COMPACTED TOGETHER a substance is (not how much something weighs)
A Bowling Ball is very dense because the atoms are COMPACTED TOGETHER
A bulletin board made of cork is not very dense because the atoms are not packed close together

13. Density
Density is INTENSIVE PHYSICAL property because it DOES NOT matter how much you have it will still have the same DENSITY

14. Density (Example) Bulletin Board is not very dense
The atoms are far apart for a solid
You can put a pin or thumb tack into a bulletin board
Now think of trying to put a pin or tack into a BOWLING BALL
You can’t because bowling balls are too dense

15. Melting Point
Melting Point is the temperature at which point a substance begins to melt
It is INTENSIVE because it does not matter how much of the substance you have it will begin melting at the same temperature

16. Melting Point (Example)
Lets use gold as an example of a substance
I can use it because it is a pure substance that is on the Periodic Table
No matter how much gold you have whether it be my wedding ring or a car made out of gold
If you heat it to 1948 degrees it will begin to melt

17. Boiling Point
Boiling Point is the temperature at which a substance begins to boil
Boiling Point is INTENSIVE because it doesn’t matter how much of the substance you have it will start boiling when it hits its boiling point

18. Boiling Point (Example)
Lets use WATER as an example
Water will boil at 212 degrees
It doesn’t matter if you have a cup of water or a bathtub of water as soon as it reaches 212 degrees it will start to boil

19. Extensive Physical Properties
Extensive Physical Properties are those properties that DEPEND ON THE AMOUNT OF MATTER of the object
Extensive Physical Properties include…
Volume
Mass
Weight

20. Volume
Volume is the AMOUNT OF SPACE that a solid, liquid or gas takes up
Volume is EXTENSIVE as it DOES DEPEND on the amount of the sample

21. Volume (Example) Lets use a cup & swimming pool for an example
Which one of these takes up more space
The one that takes up more space will have a GREATER/BIGGER VOLUME (swimming pool)

22. Mass
Mass is the amount of MATTER a substance contains & it never changes
Mass is EXTENSIVE as it DOES DEPEND on how big the sample is

23. Mass (Example) Lets us an elephant and a baby as an example
The larger the sample the LARGER/BIGGER the mass
Because the elephant is bigger it will have more mass
But don’t get confused it will have the same mass no matter where it is (Earth or Space)

24. Weight Weight is the FORCE OF GRAVITY on an object
Weight is EXTENSIVE as it DOES DEPEND on where the sample is

25. Weight
This means the more gravity in a place the more the substance will weigh (it will still have the same mass though)
Weight will change depending on where the substance is because of GRAVITY

26. Weight (Example) We will use Earth & the Moon as an example
Where will a person weigh more Earth or the Moon
There is more GRAVITY pulling us to Earth because it is bigger it has a larger GRAVITATIONAL PULL
This means we will WEIGH more there

27. EOG Questions How does 250 mL of water compare to 500 mL of water?
A) They have the same melting point but different boiling points.
B) They have the same boiling point but different melting points.
C) They have the same volume but different densities.
D) They have the same density but different volumes.

28. Important Points
Properties of Pure substances can be either INTENSIVE or EXTENSIVE
INTENSIVE means that no matter how much or where the substance is the properties will be the same
EXTENSIVE means that properties depend on either how big the sample is or where the sample is
There are 4 INTENSIVE properties
Solubility
Density
Melting Point
Boiling Point
There are 3 EXTNESIVE properties
Volume
Mass
Weight