Density

Definition

Density: The amount of matter in a certain volume. (How much matter is

in a given amount of space.)

Example:Each of the spheres in these boxes have the same mass, which box has a higher density?

Calculations

There is only one equation for density calculations:

D = m / v

Density = mass / volume

Calculations

Mass is mass, but

sometimes, calculating volume can be trickier.

Measuring Volume

What is Volume?Volume is the amount of space

something occupies.

Everything has volume.

Everything takes up space.

Know Your Equipment

There are two pieces of lab equipment that you will use to measure volume.

1. Graduated Cylinder

2. Meter Stick

Know Your Equipment

Graduated cylinders are

used to measure liquid volume as well as the volume

of irregular objects.

Know Your Equipment

Read measurements based on the bottom of the meniscus.

Know Your Equipment

What is the volume of this

graduated cylinder?

Know Your EquipmentTo calculate the

volume of an irregular object, use the following

steps:1. Calculate volume without

object.2. Calculate volume with

object.3. Subtract the

values to find the volume of

the object.

Know Your Equipment

So, what is the volume

of the action figure?

Know Your Equipment

A meter stick is used to measure

geometric volume.

The formula for rectangular prism or

cube volume is:Length x Width x

Height10 cm

9 cm

8 cm

Know Your Equipment

What is the volume of this

cube? The formula for rectangular prism or

cube volume is:Length x Width x

Height

10 cm

9 cm

8 cm

Density and Water

Water has a density of 1 g/cm3 (or 1 g/mL). This means that a cube of water exactly 1cm3 large would have a mass of exactly 1 gram.

Think About It:What would have a

higher density: Distilled water or salt

water?Why?

Density and Water

Density of Object > 1 g/cm3 = Sinks in Water

Density of Object < 1 g/cm3 = Floats on Water