Density
Read through the PPT and take notes
on Density. Don’t forget a Title and a
subtitle for each section!
Hint: Titles are underlined & Important things are in red.
What is density?
Density is a comparison of
how much matter
there is in a certain
amount of space.
Density is the measure of the
“compactness” of a material.
Density is determined by how close the
atoms are to each other
“Compactness”
All substances have density including
liquids, solids, and gases
Density is a RATIO of mass to volume.
If the temperature stays the same, the
Density of solids & liquids do not change…
discuss this.
Because of this density is a Characteristic
Property and is used to help identify
unknown substances.
If you take the same volume of different substances,
then they will weigh different amounts.
Wood
Water
Iron
1 cm3
1 cm3
1 cm3
0.50 g
1.00 g
8.00 g
IRON
Q) Which has the greatest mass and therefore the most dense?
Which one is more dense?
Demonstration: Hula-hoop Density… try it!
How about this: Which square is more dense?
Why?
If the volume is the same but the mass is higher then density will
be higher - More matter in the same space!
Illustrate and label the two different densities as more & less dense.
Which one is more dense?
Now which one is more dense?
Why?
If the mass is the same but the volume is smaller . . . The
density will be higher. Same amount of matter but a smaller
volume or space!
Illustrate and label the two different densities as high & low.
How do we determine density?
To calculate the density of something:
Density = mass ÷ volume OR
Units for density:
g
cm3
 Why are these the units for density?
mass OR m
volume
v
ALWAYS
REMEMBER
UNITS!
A little trick to remember!
I
DENSITY
Let’s try a density problem together
Frank has a paper clip. It has a mass of 9g
and a volume of 3cm3. What is its density?
M
g
D= V
D = cm3
D = 39cmg 3 D = 3 cmg
3
Frank also has an eraser. It has a mass of
3g, and a volume of 1cm3. What is its
density?
3g
g
M
D = V
D = cm3
D = 1cm3 D = 3 cmg
3
Work on these problems with your neighbor.
Jack has a rock. The rock has a mass of
6g and a volume of 3cm3. What is the
density of the rock?
Jill has a gel pen. The gel pen has a mass
of 8g and a volume of 2cm3. What is the
density of the pen?
Now, try these on your own.
Al’Licia has a watch. It has a mass of 4g
and a volume of 2cm3. What is the density
of the watch?
Mia has a wallet. It has a mass of 15g and
a volume of 5cm3. What is the density of
the wallet?
Think about it… Do water and ice
have the same density?
Proof that ice and water have
DIFFERENT densities!
What would happen????
Mercury density = 13,600 kg/m3
Lead density = 11,340 kg/m3
Lead floats on liquid
mercury!
Liquid Layers
If you pour together liquids that don’t mix
and have different densities, they will form
liquid layers.
Can you think of examples?
Let’s Do a Demonstration: Density Column
The liquid with the lowest density (NOT
very dense) will be on the top or float..
The liquid with the highest density (more
dense) will be on the bottom or sink.
Liquid Layers
 Check out this picture from your book.
Which layer has the highest density?
 Which layer has the lowest density?
 Imagine that the liquids have the following
densities (remember liquid volume is mL or L):
10 g/mL
3 g/mL
6 g/mL
5 g/mL
 Which density would belong with which
layer?
Liquid Layers – Try with your neighbor
 Which liquid has the
highest density?
 Which liquid has the
lowest density?
 Which liquid has the
middle density?
Liquid Layers – Try on your own!
 Imagine that the
liquids on the right
have the following
densities:
15 g/mL
3 g/mL
7 g/mL
10 g/mL
9 g/mL
12 g/mL
 Match the colors to
the correct densities.
3g/mL
7g/mL
9g/mL
10g/mL
12g/mL
15g/mL
Review
What is the formula for density?
What happens if you pour together liquids
that have different densities?
Will the liquid on the top have the highest
or lowest density?
Will the liquid on the bottom have the
highest or lowest density?
Super Scientist Question of the Day
Jake has a book, a ruler, and a balance.
Explain how can Jake find the density
of the book with the tools he has?