Y8: Balancing Equations

• Chemistry
• Lower Secondary (Key Stage 3)

Y8: Balancing Equations

How many oxygen atoms are there in each of these substances?

Substance	Oxygen Atoms
O
HNO
C H O
MgO
CO
MgCO

2

2

3

3

6

12

6

1

2

2

3

3

6

In a balanced equation the number of atoms of each element is the same on each side of the arrow.

Is this equation balanced?

1. Yes
2. No

Is this equation balanced?

1. Yes
2. No

Is this equation balanced?

1. Yes
2. No

Is this equation balanced?

1. Yes
2. No

To balance an equation we can multiply any of the existing substances until the number of atoms is equal.

Add one molecule to balance the  equation.

Add one molecule to balance the  equation.

Add two molecules to balance the equation.

Add two molecules to balance the  equation.

Add three molecules to balance the  equation.

Add two molecules to balance the  equation.