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Chemical Reactions: fun facts and quiz
The essentials in 7 ideas, with fun facts, an illustrated story and a quiz to see how much you know.
The essentials
What a Reaction Is
In a chemical reaction, atoms rearrange to make new substances. Signs include bubbles, colour changes, light or heat.
Key fact
Melting ice isn’t a reaction: it’s still water.
Nothing Is Lost
In a reaction, atoms aren’t created or destroyed, just rearranged. So the total mass stays the same, as Antoine Lavoisier showed in the 1700s.
Key fact
When wood burns, the “missing” mass goes off as gases.
Combustion
Burning, or combustion, is a fast reaction with oxygen that releases heat and light. A fire needs fuel, oxygen and heat: take one away and it goes out.
Key fact
Fuel, oxygen and heat are called the fire triangle.
Faster Reactions
Heat, stirring, smaller pieces and catalysts all speed reactions up. That’s why food goes off faster out of the fridge.
Key fact
A catalyst speeds up a reaction without being used up.
Catalysts & Enzymes
Enzymes are the body’s catalysts: proteins that speed up reactions like digestion. Car catalytic converters use metals like platinum to clean up exhaust.
Key fact
Some enzymes speed reactions up millions of times.
Fireworks
Fireworks get their colours from metal compounds: strontium burns red, sodium yellow, barium green and copper blue.
Key fact
Gunpowder was invented in China over 1,000 years ago.
Reversible Reactions
Some reactions can run both ways. In a rechargeable battery, charging pushes the reaction back, ready to release energy again.
Key fact
The Haber process makes ammonia for fertiliser with a reversible reaction.
Fun facts
Cooking is chemistry: once a cake is baked, nothing can turn it back into eggs, flour and sugar.
Antoine Lavoisier, who showed that mass is never lost, was executed during the French Revolution in 1794.
In space, candle flames are round and blue: without gravity, hot air doesn’t rise to stretch them into a point.
Flour dust in the air can explode: each tiny grain burns so fast that old flour mills have been blown apart.
Biological washing powders contain enzymes that break down stains like blood and grass.
Blue is the hardest firework colour to make.
Heat blue copper sulfate crystals and they turn white; add a drop of water and they turn blue again.
Story: The Chemist and His Scales
The Chemist and His Scales
1770s, Paris. Antoine Lavoisier and his wife, Marie-Anne, weigh everything before and after reactions, gases included.
Their precise scales show that mass is never lost, only rearranged. Marie-Anne records the results and draws the equipment.
In 1794, during the French Revolution, Lavoisier was guillotined, not for his science but for his old job collecting taxes.
True or false?
Tap your answer to see if you got it, and why.
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Question 1 of 10
A chemical reaction makes new substances.
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True. The atoms join up in new ways.
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Question 2 of 10
In chemical reactions, atoms are rearranged, not destroyed.
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True. Every atom is still there afterwards.
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Question 3 of 10
A fire needs oxygen to keep burning.
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True. Starve it of air and it dies.
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Question 4 of 10
Warmer temperatures usually speed up reactions.
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True. Particles move faster and collide more.
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Question 5 of 10
Enzymes are biological catalysts.
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True. They speed up the chemistry of life.
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Question 6 of 10
Firework colours come from metal compounds.
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True. Each metal glows its own colour.
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Question 7 of 10
Recharging a battery reverses a chemical reaction.
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True. Charging pushes the reaction backwards.
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Question 8 of 10
Melting ice is a chemical reaction.
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False. It’s a change of state; it’s still water.
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Question 9 of 10
Burning wood destroys most of its atoms.
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False. Its atoms leave as smoke and gases.
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Question 10 of 10
Water puts out fires by adding fuel.
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False. Water cools the fire and cuts off air.
Keep going in the app
KnowSoda learns what you know and brings back what you’re about to forget. Chemical Reactions has 6 more ideas at the Advanced and Expert levels.
Sources
- Royal Society of Chemistry — Chemical reactions and rates
- American Chemical Society — The chemistry of fireworks
- Encyclopaedia Britannica — Lavoisier, combustion, catalysis, Haber–Bosch process
- OpenStax — Chemistry 2e
- American Chemical Society — Green chemistry principles; Hall–Héroult process
- The Nobel Prize — Alfred Nobel’s life and work
- Encyclopaedia Britannica — dynamite, nitroglycerin
