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Activity 3.7 — Metals with Water
NCERT Activity 3.7: Drop small pieces of sodium, calcium, magnesium, and iron into separate beakers of cold water. Observe how the reactivity decreases from sodium (vigorous, exothermic) to iron (no reaction at all).
How To Perform
1
Add Sodium (Na)
Drop sodium into water — vigorous reaction, H₂ catches fire!
2
Add Calcium (Ca)
Drop calcium into water — steady bubbles, water turns milky.
3
Add Magnesium (Mg)
Place magnesium in water — very slow, tiny bubbles after a while.
4
Add Iron (Fe)
Place iron in water — no reaction with cold water.
5
Conclude
Reactivity decreases: Na > Ca > Mg > Fe. Iron only reacts with steam.
⚠️ Safety Notes
- •Sodium reacts EXPLOSIVELY with water — never handle with bare hands. Use forceps and keep away from water until the experiment.
- •The hydrogen produced can catch fire — keep flammable materials away.
- •Calcium hydroxide is mildly caustic — wash hands after handling.