This topic summary covers Knowledge Organiser: Reactivity Series within The Reactivity Series for GCSE Chemistry. Revise The Reactivity Series in Chemical Changes for GCSE Chemistry with 28 exam-style questions and 20 flashcards. This topic shows up very often in GCSE exams, so students should be able to explain it clearly, not just recognise the term. It is section 12 of 12 in this topic. Use this topic summary to connect the idea to the wider topic before moving on to questions and flashcards.
Knowledge Organiser: Reactivity Series
Key Terms
- Reactivity: ease of losing outer electrons
- Oxidation: loss of electrons
- Reduction: gain of electrons
- Electrolysis: extraction above carbon
- Carbon reduction: extraction below carbon
- Native: found uncombined (Au, Ag, Pt)
Must-Know Facts
- Order: K > Na > Li > Ca > Mg > Al > C > Zn > Fe > H > Cu > Ag > Au
- K, Na, Li, Ca react vigorously with cold water → hydroxide + H₂
- Mg reacts slowly with cold water; vigorously with steam
- Zn, Fe react with steam only (not cold water)
- Metals above H react with dilute acid → salt + H₂
- Above C → electrolysis; below C → carbon reduction
- Reactivity: more shells + more shielding = weaker pull on outer electron = more reactive
Key Equations
- 2Na + 2H₂O → 2NaOH + H₂ (sodium + water)
- Mg + 2HCl → MgCl₂ + H₂ (metal + acid)
- 2Fe₂O₃ + 3C → 4Fe + 3CO₂ (carbon reduction of iron ore)
Common Mistakes
- Saying aluminium is less reactive than it appears: Aluminium has a protective oxide layer that prevents further reaction — it is actually very reactive
- Getting extraction method wrong: Metals above carbon in the reactivity series (e.g. aluminium, sodium) must be extracted by electrolysis — carbon cannot reduce them
- Confusing oxidation and reduction: OIL RIG — Oxidation Is Loss (of electrons); Reduction Is Gain (of electrons)
- Saying gold is found as a compound: Gold is below hydrogen in the reactivity series — it is found native (uncombined) in the Earth's crust
Practice questions for The Reactivity Series
Which of the following shows metals listed in order from MOST reactive to LEAST reactive?
Iron filings are added to copper sulfate solution. Explain what happens, including what is observed and why the reaction occurs.
Quick recall flashcards
How do you test for hydrogen gas?
Hold a lighted splint near the gas — makes a 'squeaky pop' sound
General equation for metal + acid
Metal + Acid → Salt + Hydrogen