alleryWhy does calcium float on water during its reaction with cold water?
ACalcium is lighter than water itself
BHydrogen bubbles collect on the metal surface
CCalcium hydroxide formed is buoyant
DOxygen bubbles lift the metal upward
Answer & Solution
Correct answer: B. Hydrogen bubbles collect on the metal surface
1. Calcium reacts with water slowly, forming calcium hydroxide and hydrogen.
2. The hydrogen gas released collects on the metal surface as bubbles.
3. These bubbles make the metal float on the water.
4. The gas is hydrogen, not oxygen, so the oxygen option is wrong.
_Source: Balbharati (Maharashtra Board) Class 10 Science & Technology, Ch 8 "Metallurgy", p.104_
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