1. each substance has its own density and can be identified by it
Characteristic
Physical Property
each substance has its own density and can be identified by it

2. Densities of Some Substances
In this picture:
What is the most dense substance?
What is the least dense?
What 2 substances have really close densities?

3. What is Density?
a measure of how closely packed the particles are in a substance
the amount of matter a substance has in a certain space (how much mass is contained per unit of volume of a substance)
A substance with a low density feels “light” and will float in a substance with a higher density.
 A substance with a high density feels “heavy” and will sink in a substance with a lower density.

4. Density as and Equation
Density (D) = Mass (m)
Volume (V)
D = m V m
D V

5. Solving Equations Use GUESS method:
G-given (state what you are given in the question)
U-unknown (state what you are trying to find)
E-Equation (write the equation and sub numbers in)
S-Solve (calculate your answer)
S-Statement (write out your answer in a full sentence)
Must use this method for full marks!!!!

6. Calculate the density of a material that has a mass of 52
Calculate the density of a material that has a mass of g and a volume of 13.5 cm3.
D= m V
= g
13.5 cm3
= g/cm3
D = ?
m = g
V = cm3
Therefore, the density of the material is g/cm3.

7. The density of silver is 10. 49 g/cm3
The density of silver is g/cm3. If a sample of pure silver has a volume of cm3, what would be the mass?
m = ?
D = g/cm3
V = cm3
m= D x V
= g/cm3 x cm3
= g
The mass of the sample would be g m
D V

8. Pure gold has a density of 19. 32 g/cm3
Pure gold has a density of g/cm3. How large would a piece of gold be if it has a mass of g?
V = m D
= g
19.32 g/cm3
= cm3
Therefore, the volume of gold would be cm3.
V = ?
D = g/cm3
m = g m
D V

9. Practice Problems Answer: 0.47 g/cm3 Answer: 19.23 cm3 Answer: 16.8 g
1) What is the density of a substance with a volume of 30 cm3 and a mass of 14 g?
Answer: 0.47 g/cm3
2) What is the volume of a substance with a density of g/cm3 and a mass of 15 g?
Answer: cm3
3) What is the mass of a substance with a density of g/cm3 and a volume of 15 mL?
Answer: 16.8 g

10. How can you measure Volume?
3 ways to measure Volume:
1) Use a ruler to measure (for regular shaped solids) and the equation V = l x w x h
2) Using a graduated cylinder (for liquids)
3) Displacement using a graduated cylinder (for irregular solids) using chart below:
Trial
Initial Volume (mL)
Final Volume
(mL)
Volume of Unknown
Unknown irregular shaped object 1 2
Average volume

11. How can you measure Mass?
For solids:
use an electronic balance
For liquids:
- use an electronic balance to mass a graduated cylinder with and without the liquid, then subtract

12. Lab Activity
Determine the identity of Unknown Materials (2 liquids and 2 solids)
- see lab sheet
Good Luck!