The reactivity series
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The teaching part (2 min) is free to watch. A free account opens the whole lecture: 2 worked examples, 4 practice questions, 2 real past-paper questions with the answers explained, the mistakes that lose marks, the full-marks tip, a one-card summary and a quick quiz.
What this lecture covers
- Gold lasts, iron rusts
- The series
- With oxygen
- With water
Read the transcript of the teaching part
Last time
Before we start: last time, in Displacement reactions and extraction, you learned these points. Here they are again on one card. Keep them in mind, because today builds on them.
Gold lasts, iron rusts
A gold ring buried for a thousand years still shines. An iron nail left in a garden is a flaky orange mess within a few years. The metals can be ranked by how readily they react, and that ranking is the reactivity series. It tells us what each metal does with water, acids and oxygen.
The series
Learn the order: potassium, sodium, calcium, magnesium, aluminium, zinc, iron, then hydrogen, copper, silver and gold. Hydrogen is not a metal, but it is placed in the list because it is a useful dividing line. The most reactive metals are at the top. They lose electrons most easily to make positive ions.
With oxygen
The more reactive the metal, the more vigorously it reacts with oxygen. Magnesium burns with a bright white flame to make magnesium oxide: 2Mg plus O 2 gives 2MgO. Copper only turns black when heated: 2Cu plus O 2 gives 2CuO. Gold does not react at all.
With water
Potassium, sodium and calcium react with cold water, giving the hydroxide and hydrogen. For calcium, Ca plus 2H 2 O gives Ca(OH) 2 plus H 2. Magnesium reacts very slowly with cold water, but quickly with steam, to make magnesium oxide and hydrogen. Zinc and iron react with steam. Copper, silver and gold do not react with water at all.
How often it comes up
How often Cambridge has asked each part, counted by ExamYard from every past paper in its question bank: Deducing order of reactivity · Reactions with water and acids · Reactivity series · Reactivity series.
Chapter 9: Metals
- The reactivity series 5 min
- Displacement reactions and extraction 5 min
- Extracting iron and aluminium 6 min
- Alloys and rust protection 5 min
Also for IGCSE Chemistry 0620
Which topics come up most in IGCSE Chemistry 0620 past papers, counted from every paper since 2004.