1. DENSITY

2. Density
Defined as the mass of a substance that occupies a certain unit volume
Determines which substance will float or sink in another substance
Also helps separate components of a mixture (example: Blood)

3. Formula
Mass
Density =
Volume

4. Units of Measurement Expressed as: grams per cubic centimetre (g/cm3)
grams per millilitre (g/mL)
But there are other units of density:
Kg/L
g/L
g/dL

5. Significant Digits
Represent the amount of uncertainty in a measurement
Are considered when calculating quantitative property like density
Should be followed when expressing final answers involving calculations
(refer to pg 556 of textbook for rules)

6. A silver nugget has a mass of 6. 00g and a volume of 0. 500 cm3
A silver nugget has a mass of 6.00g and a volume of cm3. What is its density?
Calculation:
D = M/V
D = 6.00g
0.500 cm3
D = 12.0g/cm3
Notice that the final answer has 3 significant digits because that is the least number of digits from the two given data

7. An unknown metal weighs 21. 6g and occupies 8. 00mL
An unknown metal weighs 21.6g and occupies 8.00mL. What is its density?
D = M/V
D = 21.6g
8.00mL
D = 2.70g/mL
The unknown metal has a density of 2.70g/mL.

8. If a material has a density of 1. 5g/mL and weighs 25
If a material has a density of 1.5g/mL and weighs 25.0g, what is its volume?
D=M/V
V=M/D
V= 25.0g
1.5g/mL
V = 17 mL
The volume of the material is 17mL.

9. V = length x width x height
Finding Volume
V = l x w x h
V = length x width x height

10. A rectangle has a length of 5cm, a width of 4 cm and a height of 2 cm
A rectangle has a length of 5cm, a width of 4 cm and a height of 2 cm. Calculate the volume of the rectangle?
Formula: V= l x w x h
Calculations: V = 5 cm x 4 cm x 2 cm
= 40 cm3
The volume of the rectangle is 40 cm3

11. Remember: Use the formula for density: D=M/V
Manipulate the formula if the problem asks for mass or volume instead of density
Follow the rules of significant digits for multiplying/dividing: final answer must have the same number of significant digits as the least given data
Convert:1mL = 1cm3

12. Work Do pg 157 #2,3,4,5 Do the worksheets on density
classwork to be taken up in 20 minutes
Do the worksheets on density
to be handed in for marks – next class