If you can write a reaction but cannot say why the observation happened, the gap is between the equation and the particles. The fix is a habit: for every observation, name the particle that changed.
This page helps when your equations are right and your explanation marks are still low. For the related skill of keeping observations and conclusions apart, see writing observations separately from inferences.
What does it sound like when this happens?
Students describe it in similar words.
- “I wrote ‘it reacts’ and got no marks.”
- “I remember the equation but not what it looks like.”
- “I can say what happened but not why.”
What is usually behind it?
Reactions get memorised as a list of equations, with the reasoning left out. The equation is a summary, and the observation is a real event that needs its own explanation.
The other cause is using the word “reacts” as if it were an answer. It names the event but not what changed.
How do you explain an observation?
Use three columns for every reaction.
| See | Mean | Particles |
|---|---|---|
| What is observed? | What does it show? | Which particle changed, and how? |
Worked example: zinc in copper(II) sulfate
Zinc foil is placed in blue copper(II) sulfate solution. The equation is Zn + CuSO₄ → ZnSO₄ + Cu.
| See | Mean | Particles |
|---|---|---|
| The blue colour fades | The blue ions are being used up | Cu²⁺ ions gain electrons and become copper atoms |
| Brown solid forms on the zinc | Copper is being deposited | Copper atoms are formed at the zinc surface |
| The zinc foil gets thinner | Zinc is dissolving | Zinc atoms lose electrons and become Zn²⁺ ions in solution |
A weak answer says: “Zinc is more reactive than copper, so it reacts.” A strong answer states each row: the blue colour fades because Cu²⁺ ions, which give the blue colour, are used up when they gain electrons.
The explanation also shows why zinc is oxidised and copper ions are reduced. The lesson on identifying oxidation and reduction builds this into a method.
What can you do this week?
- Choose five reactions from your notes.
- For each, draw the see, mean, particles table from memory.
- Check against your textbook and fill in what you missed.
- Mark each row: was the explanation about particles or only about the reaction?
The mole and stoichiometry steps tool helps when the question adds a calculation after the explanation.
When might one-to-one tuition help?
If the three columns feel easy on paper but the wording slips under exam conditions, a teacher can ask “why?” after each line you write. Practising with someone who responds is quicker than checking alone.
See online one-to-one Chemistry tuition for how starting works. Keep a mistake log so you can see which reasons you miss most.