Balancing Equations
Class 10 Science: chemical reactions and equations
Change the numbers in front of each formula until every atom balances on both sides.
Words to know
- Reactant
- A substance you start with, on the left of the arrow.
- Product
- A substance made in the reaction, on the right.
- Coefficient
- The big number in front of a formula; it counts molecules.
- Law of conservation of mass
- Atoms are not made or destroyed in a reaction, only rearranged.
Quick check
Answer 3 questions to check what you learned.
Try at home
Use coloured beads or paper circles as atoms: two red (H) for H₂ and two blue (O) for O₂. How many H₂ and O₂ do you need to build two H₂O without any left over?