Elements and Compounds

OC3 classification and properties of elements, compounds and mixtures

  1. understand what an element is and recall that all known elements are listed in the Periodic Table;

An element is a pure substance that has only one type of atom in it.

All elements have a 1 word Name and a Symbol and can be found on the periodic table

all known elements are listed in the Periodic Table;

  1. recall that when elements combine to form compounds they may lose their individual properties

A compound is made up of 2 or more different elements that react in a fixed ratio.

Name 5 materials that are NOT on the periodic table

If these materials are not on the Periodic table

then they are NOT ELEMENTS

These materials are compounds of different elements

OC4 examine a variety of substances and classify these as

elements or compounds

A molecule is where 2 or more atoms become chemically combined

A compound is where there are at least 2 different types of atoms combined in the molecule.

  • Use the Letter E to denote any elements
  • Use the Letter the C to denote any compounds
  • Use the Letter M to denote any Molecules
  • Use the Letter X to denote any Mixtures

(using the Periodic Table as a reference)

OC13 compare mixtures and compounds made from the same constituents, and understand that an alloy is a mixture

difference between a mixture and a pure substance.

Materials (solids, liquids, gases) can be mixed or pure,

if we say something is pure then it means that all the particles that make up the object are exactly the same.

understand what a compound is and what a mixture is;

Compounds are also pure substances, but they are formed from Chemical Reactions. These chemical reactions involve 2 or more different elements.

Some Compounds have a one word name, but most compounds have multi word names (these names usually indicate what elements are contained in the compound)

Mixtures, Compounds and Elements,

  1. Mixtures are Not pure substances.
  2. Elements are pure and in the periodic table
  3. Compounds are pure substances, made by chemically combining 2 or more elements.

Compounds are 2 or more chemicals that are chemically combined. Compounds are almost impossible to break down!

Mixtures are 2 or more chemicals that are not chemically combined. Mixtures can often be easily separated,

The properties of a compound are not like the elements from which they are formed.

All the elements are listed off for you here!

To Investigate Mixtures and Compounds



  1. Take some Iron Filings & some Sulphur powder, observe and write down the properties you see about these substances
  2. On a sheet of white paper mix the 2 substances.
  3. In our notes it says it is easy to separate a mixture, think about how you can separate the mixture.
  4. Separate the mixture.
  5. Remix the mixture and put into a test-tube.
  6. Set the testtube up as in the diagram.
  7. Heat the bottom of the test tube, observe what is happening in the test tube.
  8. Attempt to separate the substance.


Describe the Iron ......

Describe the Sulfur ......

How can you separate the Iron & Sulfur ?

What happened when you heated the mixture?

Can you separate the mixture after it has been heated ?

OC12 compare the properties of the simple compounds H2O, CO2, MgO and FeS to those of the constituent elements

we can separate Iron and Sulphur by a magnet

Sulphur + Iron → Iron Sulphide

Yellow blackish/grey Redish ....

Can we separate Iron Sulphide ???

No, it is chemically combined .... into a COMPOUND!!

H2O Hydrogen + Oxygen → Water (hydrogen oxide)

(gas) (gas) (liquid)

CO2 Carbon + Oxygen → Carbon Dioxide

(solid) (gas) (gas)


Write Up Demonstration !


Another Experiment you could try is

Lead Nitrate mixed with Potassium Iodide, non exact volumes required. Check it out ....

OC4 examine a variety of substances and classify these as

• elements or compounds

(using the Periodic Table as a reference)

• metals or non-metals

OC5 list the physical properties (state and colour only) of two examples of metallic & 2 examples of non-metallic elements

elements and their properties