1. What are Physical Properties and Changes
Chapter 14, Lesson 2

2. Changing the state of Matter
All Matter can exist in the different states of matter (solids, liquids & gases).
To differentiate between states of matter:
Hold an Aluminum soft-drink can in your hand.(look at it , feel it ).
Run some water through your fingers ( liquid).
Take a deep breath ( feel your chest expand with air made up of gases).

3. Matter Changes
It’s hard to think about some solids such as aluminum, becoming liquid or gas .But in fact aluminum can change state at very high temperature, aluminum melts!!

4. Matter Changes
Aluminum & salt have high melting & boiling points ( it takes high temperature to turn salt or aluminum into liquid or gas).
Note: melting points are always lower than boiling points. .(melting & boiling points
of water??)

5. Matter Changes
Also substances that are gases at room temperature can be changed into liquids & solids.
Very low temperatures make this happen.
It takes extreme conditions to turn nitrogen gas into a liquid or solid.
Nitrogen has low melting & boiling points( below 0 c ).

6. Any characteristic that can be observed or measured is a physical property.
States of matter (solid, liquid & gases) are physical properties.
Also melting & boiling points are physical properties.
Another physical property is “Density” which is a useful idea in Science.
Physical properties can be used to identify, classify, and separate substances.                                                   

7. I. Density: is the amount of mass a material has for a given volume.
Density is a measure of how closely packed an object’s atoms are.
It shows the relationship between mass & volume.
To find density= Mass ÷ Volume.
The larger the volume for the same mass , the less dense an object is (D=M/V).
The greater the mass for the same volume, the more dense the object is.

8. Circle the picture that is more Dense.

9. Circle the picture that is more Dense?

10. I. Most substances have densities that don’t change.
In fact if you know that a substance is an element, you can figure out which element it is just by knowing its density; every substance has its own density.

11.                                                            I. Question 1:
Calculate the density of lead from the information: A 2 cm3 block has a mass of g
D= M/V
Density= ÷ 2 = g/cm3.

12.                                                            I. Question 2:
Find the mass of 1 cm3 block of Carbon which has a density of 1.82 g/cm3??
D= M/V
1.82= mass ÷ 1
1.82= mass/1, so mass = 1.82 g.