1. Elements, Compounds & Mixtures
D. Crowley, 2007

2. Elements, Compounds & Mixtures
To understand the difference between an element, a compound and a mixture

3. Element or compound?
Look at the pictures below - is it an element or a compound?
Element
Element
Compound
Element
Compound

4. Element or compound? How about this - element or compound?
Actually this is neither an element or a compound - it is a mixture!

5. Mixture How can we describe a mixture?
Remember: an element is made up of just one type of atom
A compound is two or more elements which are chemically bound together…
A mixture is made from different substances which are not chemically bound

6. Sweets
Imagine coloured sweets which can be mixed together in a packet, but are not chemically joined together
You could easily separate these into their different colours - without needing a chemical reaction…
Mixture
Element 1
Element 2
Element 3
Element 4

7. Definition
A mixture is made from different substances, which are not chemically bound
E.g. air is a mixture of gases
The gases (oxygen; nitrogen; argon; and carbon dioxide) can be easily separated
The properties of the mixture are just a mixture of the properties of the separate parts!!!

8. Properties
Remember, in a compound a chemical reaction binds the substances together.
This means the properties of the newly formed compound are different from the original elements
In a mixture no chemical reaction occurs
So the properties of the mixture is a mixture of all the properties that make the mixture up!

9. Mixture Example
E.g. a mixture of iron powder and sulphur powder will show properties of both iron and sulphur!
This means our mixture will contain grey magnetic bits of iron + yellow bits of sulphur

10. Examples
Look at the following - copy down the particle boxes, and decide if it represents an element, compound or mixture
Element
Element
Compound
Mixture
Mixture

11. Summary An element contains just one type of atom
A compound contains two or more types of atoms that are chemically bound
A mixture contains two or more different substances, that are not chemically bound
The different substances in a mixture can be elements or compounds

12. Mixture of elements & compounds
Summary
Copy out the table, given a description of the diagram (e.g. pure element, mixture of elements, compound etc…)
Add an example to your description
Diagram
Description
Example
Pure element
Oxygen
Pure compound
Carbon dioxide
Mixture of elements
Oxygen & Helium
Mixture of compounds
Alcohol & Water
Mixture of elements & compounds
Air

13. Quiz Try the online quiz: -