# Symbol equations

- Symbol equations have a few rules
- Symbol equations must be balanced since atoms are not created or destroyed in a chemical reaction
- A small number applies only to the element it is right of
- Example: \(O_2 = 2 \times O\)

- A small number outside a bracket applies to all elements in the bracket by multiplying
- Example: \((CO_3)_3 = 3 \times C, 9 \times O\)

- A big number applies to all elements that are to the right by multiplying
- Example: \(2H_2O = 4 \times H,\ 2 \times O\)

- The formula can never be changed when balancing an equation
- This means that you can only add a number in front of a formula

- To balance symbol equations:
- Write down the equation in full
- Write down the number of atoms on each side
- When you add numbers, make sure the change the number of atoms
- Continue until both sides are equal