TalentJR apps
You need: a sachet of dry yeast, two spoons of sugar, warm (not hot) water, a small plastic bottle and a balloon. What happens: after 20–30 minutes the mixture froths and the balloon slowly blows up. Why: yeast is a tiny living fungus. In warm water it feeds on the sugar and gives out carbon dioxide gas, which fills the balloon. This is how yeast makes bread dough rise. Cold water slows it down and very hot water kills it.
✓ You passed this lesson’s test.
Yeast is alive — “yeast feeds on sugar in warm water and gives out carbon dioxide”
Use it for: Class 6–8 science lessons on micro-organisms; a slow, amazing experiment for kids at home.
Check: Without sugar, the balloon hardly grows — no food for the yeast ✓
▶ Watch it animatedWork it out in your head or on paper, type the answer and press Check. Stuck? Press “Show me how”.
Right: 0 · Tried: 0
20 questions. Check each answer, then go to the next one. Get 16 or more right to pass.
🏅 Sign in with Google to earn the 🍞 Yeast Balloon Boss badge when you pass — and a certificate when you finish all 10 lessons of Part 2 · Kitchen chemistry and life. You can still take the test without signing in.
Why does it work? When should you use it? Ask in English, मराठी or हिंदी.
Sign in with Google to ask Free — 20 questions a day.
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