1. The document describes how iron and magnesium react with oxygen through combustion reactions. When iron reacts with oxygen, iron oxide is formed, appearing as a grayish solid. A practical investigation demonstrates how steel wool burns with a yellow flame and leaves behind iron oxide. 2. Similarly, when magnesium reacts with oxygen, magnesium oxide is produced as a white powder. Magnesium burns with an extremely bright white flame. 3. Both reactions involve the metal combining with oxygen to form an oxide. The balanced chemical equations are provided.

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3. New Words
Combustion
the chemical process in which
a substance reacts rapidly with
oxygen and gives off heat
Metal Oxide
the product formed when a
metal reacts with oxygen
Rust
an orange-brown solid that forms
on metal and flakes off easily
the addition of oxygen to an
element and the loss of electrons
Oxidation

4. Properties and Examples of Metals
• a solid material at room temperature
• conducts heat and electricity
• hard, shiny, and malleable
• tends to donate electrons
Examples
Iron
Magnesium
Copper
Silver
Tin
Properties

5. The reaction of Iron
with Oxygen
The General Reaction
Some metals react with oxygen in a process called combustion.
When these metals are burnt in air containing oxygen, the product
is called a metal oxide.
Let’s look at two examples:
The reaction of Magnesium
with Oxygen

6. Picture Equation
+
Oxygen Iron
Reaction of Iron with Oxygen
When iron is burnt in air that contains oxygen,
the product formed is iron oxide.
Word Equation:
iron + oxygen iron oxide
Chemical Equation:
Fe + O2 Fe2O3

7. Reaction of Iron with Oxygen
Practical Investigation
We will use steel wool in the demonstration.
Steel wool is wire wool made of very fine steel
threads. Steel is an alloy made mostly of iron.
The teacher can do
this investigation to
demonstrate what
happens when iron
reacts with oxygen.
You will need:
• Steel wool
• Long-nose pliers
• Bunsen/spirit burner
• Matches
• Safety goggles

8. Reaction of Iron with Oxygen
Practical Investigation
Procedure:
Use the pliers to hold a
small amount of steel wool.
Place the steel wool over the
flame of the bunsen burner.
Observe what happens.
1.
2.
3.

9. Reaction of Iron with Oxygen
Practical Investigation
Observation:
• The heat cause the iron to react with oxygen
surrounding the steel wool.
• This reaction creates the spark we see and release
of heat that heats up the next iron molecule.
• The very bright light is because of the extreme heat.
• Once the steel wool has burnt, it is a greyish colour
and can no longer be ignited. This is proof that the
steel wool has been chemically changed into the
compound of oxide.

10. Reaction of Iron with Oxygen
Practical Investigation
What was the colour of the flame of the burning iron?
A: Yellow
What is the colour of the product formed?
Name the product formed?
Write a balanced chemical reaction for
the reaction between iron and oxygen.
1.
2.
3.
4.
A: Brown
A: Iron oxide
A: 4Fe2 + 3O2 2Fe2O3

11. Reaction of Magnesium with Oxygen
When magnesium is burnt in air that contains oxygen,
the product formed is magnesium oxide.
Word Equation:
magnesium + oxygen magnesium
Chemical Equation:
Mg + O2 MgO
Picture Equation
+
Oxygen Iron

12. Reaction of Magnesium with
Oxygen Practical Investigation
We will use Magnesium ribbon in the
demonstration.
A thin ribbon of magnesium metal is used in
laboratory demonstrations and in the
magnesium lamp.
The teacher can do
this investigation to
demonstrate what
happens when
magnesium reacts
with oxygen.
You will need:
• Piece of magnesium ribbon
• Long-nose pliers
• Bunsen/spirit burner
• Matches
• Safety goggles

13. Reaction of Magnesium with Oxygen
Practical Investigation
Procedure:
Take about 50mm of
magnesium ribbon.
Use the pliers to hold a small
amount of magnesium ribbon.
Place the magnesium ribbon in
the flame of the bunsen burner
until it ignites.
1.
2.
3.
Observe what happens.
4.

14. Reaction of Magnesium with Oxygen
Practical Investigation
• When the magnesium metal burns,
it reacts with oxygen found in the air
to form magnesium oxide.
Observation:
• After it burns, it forms a white powder,
which is magnesium oxide.
• Oxygen and Magnesium combine in a chemical
reaction to form this compound.
• The ribbon burns with a blinding white flame.

15. Reaction of Iron with Oxygen
Practical Investigation
What was the colour of the flame of the burning magnesium?
A: Blinding white light
What is the colour of the product formed?
Name the product formed?
Write a balanced chemical reaction for the reaction
between iron and oxygen.
1.
2.
3.
4.
A: white
A: Magnesium oxide
A: 2Mg + O2 2MgO