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Density and
Volume
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Question:
Which weighs more:
A kilogram of feathers or a kilogram of iron
How about:
A 1 cm3 of feathers or a 1 cm3 of iron
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cm3 = volume
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If you take the same masses of three different substances,
obviously they will have the same masses
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If you take the same volume of three different substances,
they will have different masses

This is because those substances have different densities
Wood
Water
Iron
1 cm3
1 cm3
1 cm3
0.50 g
1.00 g
8.00 g
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So… what is density?
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Density is the proximity (closeness) of like atoms or molecules
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Density is a comparison of how much matter there is in a certain
amount of space
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Density is a measurement of not just the “heaviness” of an object,
but also how much space an object takes up!!

All substances have density including liquids, solids, and gases
Liquid Layers
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Which layer has the highest
density?
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Which layer has the lowest
density?
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Imagine that the liquids have
the following densities:
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
10g/cm3 -- 3g/cm3
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6g/cm3 -- 5g/cm3
Which number would go with
which layer?
Liquid Layers – Try on your own!
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Imagine that the liquids on
the right have the following
densities:
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15g/cm3
10g/cm3
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3g/cm3
9g/cm3
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7g/cm3
12g/cm3
Match the colors to the
correct densities.
3g/cm3
7g/cm3
9g/cm3
10g/cm3
12g/cm3
15g/cm3
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Which one is more dense?
A
local demonstration for the new school dress
code is scheduled on 2 consecutive days in the
town square
 Assume everyone has identical mass
 Which
day is more dense?
Day 1
Day 2
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Which one is more dense?
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Now which day is more dense?
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Objects that float
Why Does an Ice cube float and a marble sink?
If the objects density is < 1.000 g/cm3 or g/mL,
THEN IT WILL FLOAT!!!!!
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Let’s try a density problem together

Josh has a paper clip. It has a mass of 9g and a volume of
3cm3. What is its density?
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Christina also has an eraser. It has a mass of 3g, and a
volume of 1cm3. What is its density?
+ Work on these problems with your neighbor.
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Peyton has a rock. The rock has a mass of 6g and a
volume of 3cm3. What is the density of the rock?
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Matt has a gel pen. The gel pen has a mass of 8g and a
volume of 2cm3. What is the density of the pen?
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Now, try these on your own.
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Riley has a watch. It has a mass of 4g and a volume of
2cm3. What is the density of the watch?
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Mia has a wallet. It has a mass of 15g and a volume of
5cm3. What is the density of the wallet?
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Now let’s try some harder ones….
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You have a stone with a mass of 620 g and a volume of
753 cm3. Find the stone’s density.
D (ρ) =
M
V
M
D V
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More…
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A liquid has a density of 0.87 g/ml. What volume is
occupied by 25 g of the liquid? (Hint: 1 cm3 = 1 mL)
D (ρ) =
M
V
M
D V
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…And One More
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An object has a volume of 825 cm3 and a density of 13.6
g/cm3. Find its mass in kilograms.
D (ρ) =
M
V
M
D V
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Review
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What is the formula for density?
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What happens if you pour together liquids that have
different densities?
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Will the liquid on the top have the highest or lowest
density?
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Will the liquid on the bottom have the highest or lowest
density?
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Super Scientist Question of the Day
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Jake has a book, a ruler, and a balance.
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How can Jake find the density of the book with the tools
he has?