EDUCATIONAL CHALLENGES
 Today is
DENSITY
Take a look at the two boxes below. Each box has the same volume. If each ball has the same mass, which box would weigh more? Why?

The box that has more balls has more mass per unit of volume. This property of matter is called density. The density of a material helps to distinguish it from other materials. Since mass is usually expressed in grams and volume in cubic centimeters, density is expressed in grams/cubic centimeter.

We can calculate density using the formula:

Density= Mass/Volume

In the previous lesson you calculated the mass and volume of two blocks. If you would like to review these sections click on the appropriate links shown at the left.

Block I

Mass = 79.4 grams

Volume=29.8 cubic cm.

Block II:

Mass= 25.4 grams

Volume=29.8 cubic cm.

Now Let's calculate the density for each of these blocks.

grams/cubic cm.
If you need a calculator one is available. Click on calculator in right frame.

grams/cubic cm.
If you need a calculator one is available. Click on calculator in right frame.

What is each block made of?

Using the table below it is now possible for you to determine what substance makes up each block.

The densities for some common substances are:

 Substance Density (gm/cu.cm) Air 0.0013 Wood (oak) 0.85 Water 1.00 Ice 0.93 Aluminum 2.7 Lead 11.3 Gold 19.3 Ethanol 0.94 Methanol 0.79