Matter

• Matter is ANYTHING that has mass and takes up space.

Matter Is All Around Us• Where is it in our classroom?

• Lab Tables• Chairs• People• Pencils• Books• Even the air.

All Matter Has Mass

• How do we find out how much matter and object contains?• Measure the mass.

• What tool do we use?• What unit?

Grams (g)

Mass vs. Weight

• The mass of an object is always the same no matter where it is located.

• Weight is a measure of the amount of gravity exerted on an object.

• We weigh less on the moon than on earth because the moon experiences less gravity. Our mass is the same.

All Matter Has Volume

• Volume • The amount of space the matter occupies

• What tools do we use?

What Units?•Liters (L)

OR•Cubic centimeters (cm3 )

Remember 1mL = 1cm3

Density• Do all things that are the same volume have

the same mass?

• Density is the amount of matter in a given space.

• Which is more dense: a 1m3 box of feathers or a 1m3

box of pennies?• Pennies – they’re not heavier, they’re more dense

Calculating Density

• Density = Mass Volume

• The unit for density is g/cm3 or g/ml

M

D VX

• Density is useful for identifying substances for two reasons:

• Density stays the same for any SIZE piece of something

• The density of one substance is usually different from that of another substance.

Fool’s Gold?• To make sure you hadn’t found more fool’s gold (iron

pyrite), you could compare the density of your nugget to the know densities on the chart.

• D= M/V• D= 96.6/5• D= 19.32 g/cm3

Substance Density (g/cm3)

Iron Pyrite 5.02

Gold 19.32

Mass= 96.6gVolume= 5cm3

BrianPop Review

Try it out!A glass marble has a volume of 5 cm3 and a mass of 13 g. What is

the density of glass?What do you know?

Volume = 5 cm3, mass = 13 gWrite the formula:

D = m/vSubstitute into the formula:

D = 13g 5 cm3 Calculate:

D = 2.6 g/cm3

Check that your units agree: Unit is g/cm3.

Unit of density is g/cm3. Units agree.Answer:

D = 2.6 g/cm3

Practice Problems1. A lead sinker has a mass of 227 g and a volume

of 20 cm3. What is the density of lead?2. A glass of milk has a volume of 100 cm3. If the

milk has a mass of 103 g, what is the density of milk?

Answers:1. 11.35 g/ cm3

2. 1.03 g/ cm3