Density is

Equal Volume

The amount of matter in a given space orvolume, a relationship between mass and

volume

Greater Density Less Density

What is Density?

Mass is:

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Amount of matter in an object

Volume is:

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The amount of space an object takes up

Displacement

A way to measure the volume of a solid byplacing it in a known amount of liquid

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How can we measure the volume of an object?

Density tells us how heavy something is for its size.

Density = MASS ÷ VOLUME

An Elephant and a Mouse have the SAME DENSITY!

Let’s practice calculating density!

25 grams of salami5 mL = density of 5g/mL

16 grams of cheese8 cubic cm. = density of 2g/cm3

Salami is more dense than Cheese!Salami is more dense than Cheese!

Each cube is the same size,but has different weight and densitiesbecause of what they are made of!

We can use DENSITY to identify one element from another.

One of these is not gold...

Fool’s Golddensity = 4.8

Real Golddensity = 19.3

Often times in chemistry, the density of a substance is compared to the density of water (1.0 g/ml).

Objects that float on water have density values less than 1 (g/ml or g/cm3)Objects that sink in water have density values greater than 1 (g/ml or g/cm3)

Water as a Standard

1 g of water has a volume of 1 ml and also1 cm3

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We can also compare density without calculating it:

Dense matter sinks in water, while less dense floats above it!

water

motor oil

cooking oil

Hydrogen and Helium are less densethan Oxygen, so they float!

Carbon dioxide (our breath) is more dense than Oxygen, so it sinks!

CO2

H

He

It is the same for gases: