The best Chemistry lesson focus is the first link in the chain where the student’s reasoning stops. This page compares four places it commonly stops.
Four focuses compared
| Focus | Sign that it fits | What lessons practise |
|---|---|---|
| Equations | Balancing or writing formulae takes guesswork | Ion charges, formulae, balancing step by step |
| Mole concept | Mass, moles and volume get mixed up | Converting between quantities with one route |
| Calculations | Setup is right but the ratio is misused | Reading the equation as a ratio |
| Written explanations | Numbers are fine, reasons are vague | Linking observations to particles |
How to trace the first wrong step
- Pick a wrong calculation and cover everything after the first line.
- Ask: is the equation correct? If not, the focus is equations.
- If the equation is correct, ask: are the moles correct? If not, the focus is the mole concept.
- If the moles are correct, check the ratio, then the final conversion.
Whichever step fails first is the first focus. Later steps look wrong only because they build on it.
An example
A student finds 2.4 g of Mg reacting with acid and gets 0.1 mol of Mg, then writes 0.2 mol of H₂ because of the “2” in front of HCl. The equation and the moles are right. The ratio is the fault, so the lesson focuses on reading ratios from the coefficient of the substances asked about.
When tuition may not be needed yet
If the student errs only in careless arithmetic, practice with a checklist may be enough. The free Chemistry guide and glossary help.
Next step
Read about one-to-one Chemistry tuition, the paid one-hour trial and how to prepare for a useful trial. The prerequisite gap finder can also help.