Balancing Equations
Change the numbers in front of each formula until the atoms balance, with a live atom counter.
About this activity
Nine chemical equations to balance, from hydrogen burning to propane combustion. Students change the big numbers in front of each formula with + and − buttons, and a table counts the atoms on each side as they go, so they can see what still needs fixing. Wrong checks get a hint about which atom to look at, and every answer comes with a short explanation of the method.
How to use Balancing Equations
- Balancing Equations is a free Chemistry activity for Years 9 to 11 that takes about 15 minutes. Try it on this page on a computer, tablet or phone: there’s nothing to download.
- In a lesson, choose Show on the board to play it together as a class.
- To set it for a class, a teacher shares it and gets a code: students type the 6-digit code at lycolearn.co.uk/join with their first name and the first letter of their surname (no accounts needed), and their scores come back to the teacher.
Students will
- Balance symbol equations using the smallest whole numbers
- Count the atoms in a formula
- Explain why equations must balance (conservation of mass)
Teaching tips
- Model the first one on the board: balance the atom that appears in only one formula on each side first.
- Extension: ask why you can’t change the small numbers (it would make a different substance).