Density

Why some things sink and others float

Rainbow Lab

Rainbow LabJar Mass of

SaltVolume of

waterFood coloring

1 1.7 g 10 mL Blue

2 1.4 g 10 mL Green

3 1.1 g 10 mL Yellow

4 0.6 g 10 mL 2 Yellow, 1 Red

5 0 g 10 mL Red

Rainbow LabJar Mass of

SaltVolume of

waterFood coloring

1 5 g 30 mL Blue

2 4.2 g 30 mL Green

3 3.2 g 30 mL Yellow

4 1.7 g 30 mL 2 Yellow, 1 Red

5 0 g 30 mL Red

What if I finish early?

Calculate the density of the cubes on lab station #8 using the equation:

Density = Mass

Volume

Rainbow Lab Analysis

Red Orange Yellow

Green Blue

Density

How much “stuff” is in a certain space.

MISCONCEPTION ALERT

Density WeightDensity Weight

Which object weighs more?

Which object is more dense?

Density of water = 1.0 g/cm3 Density of gold = 19.3 g/cm3

Density

How much matter (mass) is in a certain volume

m

Vd

m

Vd

Let’s see what happens when we change one variableThink about your

knowledge of fractions from

math class

If mass gets bigger…

…and volume stays the same

What happens to density?

20 kilograms

40 kilograms

If volume gets bigger…

…and mass stays the same

What happens to density?

20 kilograms

If mass gets bigger…

…and density stays the same

What happens to volume?

20 kilograms

40 kilograms

If density gets smaller…

…and volume stays the same

What happens to mass?

20 kilograms

10 kilograms

Sink or float?

Sink or float?

Water has a density of 1.0 g/mL.

Therefore, any object with a density of LESS than 1.0 g/mL will FLOAT in water.

Anything with a density of MORE than 1.0 g/mL will SINKSINK.

Layers

Why did the colors in rainbow lab work when we used the same materials for each color?