1. The Properties of Matter
Chapter 2
The Properties of Matter

2. Section 1
What is matter?

3. Matter is anything that has mass and takes up space.
Volume is the amount of space taken up or occupied by an object.
All matter has volume

4. Volume of a regularly shaped solid object
Expressed in cubic units
The word cubic means having 3-dimensions
Units most often expressed in cubic meters (m3) or cubic centimeters (cm3)
Formula:
Volume = length x width x height

5. Liquid volume:
Liters and milliliters are the units typically used to express the volume of liquids
The tool used to measure liquid volume in science is the graduated cylinder
The meniscus is the curve at a liquid’s surface by which one measures the volume of the liquid.

6. Volume of an irregularly shaped solid object
Cannot use simple equation
Measure using the displacement method. Measure how much water the object displaces.
Because 1 mL = 1 cm3, you can express the volume in cm3

7. Matter and Mass A second characteristic of all matter is mass
Mass is the amount of matter in an object
The mass of an object stays the same no matter where the object is at in the universe.

8. Difference between mass and weight
They do not mean the same thing
Mass is the amount of matter in an object
Weight is a measure of the gravitational force exerted on an object
Value can change with the location of the object in the universe

9. For example…

10. Measuring mass and weight
Weight is a measure of gravitational force
Expressed in the SI unit of force, the Newton (N)
1 Newton = the weight of an object that has a mass of 100 grams on Earth

11. Inertia
Inertia is the tendency of an object to resist being moved or, if the object is moving, to resist a change in speed or direction until acted on by an outside force
Mass is the measure of inertia
Large mass = harder to move and harder to stop

12. A student has a mass of 45,000 g. How much does this student weigh in Newtons?

13. Section 2
Physical Properties

14. What are physical properties?
Characteristics of a substance that does not involve a chemical change, such as density, color, or hardness
Some examples of physical properties are…
Thermal conductivity
State
Density
Solubility
Ductility
Malleability
See page 45

15. Identifying physical properties…
Physical properties are identified through observation using the five senses

16. Physical Changes Do Not Form New Substances
A physical change is a change of matter from one form to another without a change in chemical properties.
Examples…

17. What is Density?
Density is a physical property that describes the relationship between mass and volume.
Density is the amount of matter in a given volume.

18. Density and liquid layers
Each type of liquid has a different density
Most dense liquid is at the bottom
Least dense liquid is at the top

19. Density of solids 1 kg of lead vs. 1 kg of feathers
Which do you want to carry around all day?
Both the feathers and the lead have the same mass
However the feathers are much less dense than lead, so it takes a lot of feathers to equal the same mass as lead
Density of Water (H2O) = 1.00 g/mL
Density of object > density of water
Object sinks
Density of object < density of water
Object floats

20. Solving for Density 1st measure the objects mass (m)
2nd measure the objects volume (V)
Then, use this equation: D = m/V
Units are typically expressed in g/cm3 (solids)
g/mL (liquids)

21. Example density problems…
What is the density of an object whose mass is 25 g and whose volume is 10 cm3
D = 2.5 g/cm3
Suppose you have a lead ball, with a volume of 40 cm3 and a mass of 454 g. What is the ball’s density?
D = g/cm3
Homework: p.49; 2-11

22. 1. ) Please lay your Ch 2 vocab cards on your desk, definition side up
1.) Please lay your Ch 2 vocab cards on your desk, definition side up. 2.) Take a few minutes and think about your personal goals.

23. In your science binder, write down a goal you're striving for this week.

24. Section 3
Chemical Properties

25. Chemical Properties
a property of matter that describes a substance’s ability to participate in chemical reactions
Examples:
Flammability: gasoline, rubbing alcohol, wood
Reactivity: Acetic Acid and baking soda, sodium metal and water

26. Comparing physical and chemical properties
What can we do with a pencil?
Break it!!!!!!!!!!!!!! = Physical change
Burn it!!!!!!!!!!!!! = Chemical change

27. Chemical changes and new substances
A chemical change occurs when one or more substances change into entirely new substances with different properties
Examples:
Every time a battery is used, if reaction fails you have a dead battery
Digestion of food

28. Physical vs. Chemical changes
Does the composition change?
The composition of an object is the type of matter that makes up the object and the way the matter is arranged in the object.
For example:
Electrolysis

29. Reversing changes Physical changes
Easily reversed because composition does not change
i.e. Ice cube melts---Refreeze
Chemical changes
Difficult to reverse because composition does change
i.e. fireworks

30. In your science journals: 1. ) Are all golf balls created equal
In your science journals: 1.) Are all golf balls created equal?  Calculate the density and weight of each golf ball. Assuming I apply the same force with a driver and all external conditions remain constant, will each ball go the same distance.   2.) Calculate the density and weight of the wood block.  Prove it will float in water?