Density

A quantitative physical property

DensityAt the conclusion of our time together, you should be able to:

1.1. Define densityDefine density2.2. Calculate the density of a given object if Calculate the density of a given object if

given the volume and massgiven the volume and mass3.3. Calculate the volume or mass if the density Calculate the volume or mass if the density

is given with the volume or massis given with the volume or mass

Definition

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?

►Which takes up more space?

►If two objects have the same mass, the one with the higher density will take up less space.

Neither

Feathers

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.

Water has a density of 1.0 g/ml and mercury (Hg) has a density of 13.6 g/ml.

Density CalculationsExample 1: A chunk of silver has a mass of 21.0 g and a volume of 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 CalculationsExample 1: A chunk of silver has a mass of 21.0 g and a volume of 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 CalculationsExample 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 CalculationsExample 3: What is the volume of a solid that has a mass of 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 – 5Let’s see if you can:

1.1. Define densityDefine density2.2. Calculate the density of a given object if Calculate the density of a given object if

given the volume and massgiven the volume and mass3.3. Calculate the volume or mass if the density Calculate the volume or mass if the density

is given with the volume or massis given with the volume or mass