Density

Density

a.

Density is a physical property of
a substance

b.

A substance with a low density
is referred to as being “light”

Ex. Balloons float because they are “lighter”

than the air around them.

c.

A substance with a high density
is referred to as being “heavy”

Ex. Earth’s core is made of iron making it more

dense (heavier) than the mantle or crust

d. By knowing the density of a substance,
you can know if the substance will float or
sink.

e. In chemistry, the density of
many substances is compared to
the density of water.
f. The density of water is 1 g/mL
g. If an object such as a piece of
wood floats on water it is less
dense than water
h. If a rock sinks in water, it is
more dense than water.

2.3 g/mL

0.04 g/mL

Question: Will the brick in the picture sink or float in water? How do you know?
What about the feather?

Density in Real Life

● Oil spills: What

happens when an oil
tanker leaks on the
ocean?

● https://www.youtube.c

om/watch?v=3DbSlAg
3F3A

Click to access the short video clip that answers
this question.

Volume

Displacement

Displacement

Density

Density

Relative Density

Relative Density

Calculating Density

The density of a substance is found by
dividing the object’s mass by its volume

D = m/v

Or

Density = mass divided by volume

Density Formula

Density Formula

Formula

M

D

V

÷

÷

x

Practice Problem

●

If we know that 10.0 cm3 of ice has a
mass of 9.17 g, what is the density of
ice?
D = m
v
D = 9.17 g
10.0 cm3

D= 0.92 g/ cm3

Practice:

A piece of tin has a mass of 16.52 g and a
volume of 2.26 cm3. What is the density of tin?

YOU TRY

Practice:

A man has a 50.0 cm3 bottle completely filled
with 163 g of a slimy green liquid. What is the
density of the liquid?

YOU TRY

Practice:

1.

A sealed 2500 cm3 flask is full to capacity with
0.36 g of a substance. Determine the density
of the substance.

YOU TRY

● What is the density of the following object?

Mass = 2 g

Volume of
Water = 50 mL

Volume of
Water = 100 mL

Answer = 0.04 g/mL

What is the density of a 15 g box measuring 10 cm by
5 cm by 2 cm?

d = ?
m = 15 g
v = ?

d = m

v
v = l x w x h

v = l x w x h
v = 10 x 5 x 2
v = 100 cm3

d = m
v

d = 15
100

d = 0.15 g/cm3