Density
Density
 Take a look at the two boxes below. Each box has the
same volume. If each ball has the same mass,
which box would weigh more? Why?
Density
 The box that has more balls has more mass per unit of
volume.
 This property of matter is called density. The density
of a material helps to distinguish it from other
materials.
 Density
 I love density
d = mass/volume (g/ml)
m
v
Mass
volume

Density = Mass of substance per unit volume of
the substance.
 Common units are g/cm3 or g/mL.
mass
Density =
volume
Example #1
A certain mineral has a mass of 17.8 g and a volume of
2.35 cm3. What is the density of this mineral?
mass
Density =
volume
17.8 g
Density =
2.35 cm3
3
Density = 7.57 g/cm
Example #2
What is the mass of a 49.6-mL sample of a liquid, which
has a density of 0.85 g/mL?
Density =
0.85 g/mL =
mass
volume
x
49.6 mL
mass = x = 42 g
Density
More practice - Calculate the density of each block.
Block I
Mass = 79.43 grams
Volume=29.8 ml
Block II
Mass = 25.41 grams
Volume = 29.8 ml
Density
 Block I
 Density = 79.43 grams / 29.8 ml
= 2.67 g/ml
 Block II
 Density = 25.41 grams / 29.8 ml
= 0.85 g/ml
Density
 Density is a physical characteristic of a material and
allows us to determine what each block is made of.
 All pieces of matter made of the same material will
have the same density.
 Different matter will have different densities.