2. To understand the difference between an element,
a compound and a mixture
3. Look at the pictures below - is it an element or a
compound?
Element
Element
Compound
Element
Compound
4. How about this - element or compound?
Actually this is neither an element or a compound - it
is a mixture!
5. 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. 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. 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. 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. 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. 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. 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. 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. Try the online quiz: http://www.bbc.co.uk/schools/ks3bitesize/science/chemistry/elements_com_mix_test.shtml