Density
A quantitative physical property
Density
At the conclusion of our time
together, you should be able to:
1. Define density
2. Calculate the density of a given object if
given the volume and mass
3. Calculate the volume or mass if the density
is given with the volume or mass
Definition
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Density is defined as mass per unit
volume
It is the amount of matter within a
certain volume
Density = mass
volume
Units = g/mL (liquid) OR g/cm3 (solid)
Which one is more dense?
Which one is more dense?
►Which is heavier, a kilogram of
feathers or a kilogram of bricks? Neither
►Which takes up more space?
Feathers
►If two objects have the
same mass, the one with the
higher density will take up
less space.
Water has a density of 1.0 g/ml and
mercury (Hg) has a density of 13.6 g/ml.
Which is heavier, a liter of water or a liter of
mercury?
If we have equal volumes of two different
substances, then the one with the greater density
will have the greater mass.
Density Calculations
Example 1:
volume of
A chunk of silver has a mass of 21.0 g and a
2.00 cm3. What is the density of silver?
Set up your density problems as shown on the handout:
Given: m = 21.0 g
V = 2.00 cm3
Required: D
Density Calculations
Example 1:
volume of
A chunk of silver has a mass of 21.0 g and a
2.00 cm3. What is the density of silver?
Analysis: D = m
V
Solution: D = 21.0
2.00 cm3
D = 10.5 g/cm3
Paraphrase: The density of silver is 10.5 g/cm3.
Density Calculations
Example 2:
The density of lead is 11.35 g/cm3. Determine the
mass of a cube of lead with sides 2.5 cm long.
Density Calculations
Example 3:
of
What is the volume of a solid that has a mass
5.00 X 104 mg and a density of 55 g/cm3?
Density Calculations
m
D
V
Cover up whatever unit you are solving for,
the two units remaining will show you how
to solve the problem.
Homework – pg. 25 # 1 – 5
Let’s see if you can:
1. Define density
2. Calculate the density of a given object if
given the volume and mass
3. Calculate the volume or mass if the density
is given with the volume or mass