1. Unit: Atoms and Elements
In this lesson, we will learn about…
Density

2. Unit: Atoms and Elements
The volume of an object is the amount of space the object takes up.
The SI (metric) unit for volume is the cubic metre (m3) and also used is the litre (L).
1 cm3 = 1 mL
That would mean there are 1000 litres in
1 m3

3. Unit: Atoms and Elements
Volumes of solids are usually measured in cubic units (cm3 or m3).
Volumes of gases and liquids are usually measured in mL or L.
How would you find the volume of a box?
What about a rock?

4. Unit: Atoms and Elements
When using a graduated cylinder,
you will notice at the top of the liquid, there is a curve called the meniscus.
When reading volumes from
a graduated cylinder,
read from the bottom
of the meniscus.

5. Unit: Atoms and Elements
The mass of an object is a measure of the amount of the substance (SI unit is the kilogram (kg) but often grams (g) are used as well).
To calculate the mass of an object, a balance is used.

6. Unit: Atoms and Elements
There is a relationship between mass and volume.
This relationship is called the density of the material.
Density describes how many particles there are in a given space.
The more particles, the denser the material is.

7. Unit: Atoms and Elements
To calculate the density of a material, divide the mass of the substance by the volume of the substance.

8. Unit: Atoms and Elements
The units for density are:
kg/m3 or g/cm3 or g/mL
eg. water has a density of
1000 kg/m3 or 1 g/cm3
Therefore if you know the mass and volume of a pure substance, you can find the density and identify the substance.

9. Unit: Atoms and Elements
Problem: A block of an unknown substance is brought to you for identification. It has a mass of 1300 kg and a volume of 0.5 m3 .
What material is the block made of?
Problem Solving Method
1. Information given
2. Formula (rearranged)
3. Plug numbers in
4. Solve and include correct units!
5. Answer Question

10. Unit: Atoms and Elements
Problem: A lump of an unknown substance is brought to you for identification. It has a mass of 1300 kg and a volume of 0.5 m3 .
What material is the lump made of?
m = 1300 kg
v = 0.5 m3
d = ?
d = m d = kg d = 2600 kg/m3
v m3
Therefore, block is made of glass!