NCERT Question 6 - Chapter 4 Class 8 - Materials : Metals And Non-Metals

Aluminium foils are used to wrap food items.

To wrap food items, we need a thin sheet.

Aluminium foils are used to wrap food items because aluminium is malleable

Which means it can be beaten into thin sheets which can be used to wrap food items

Immersion rods for heating liquids are made up of metallic substances.

Metals are good conductors of heat and electricity. Immersion rods for heating liquids are made up of metallic substances because being good conductors of heat, they'll be able to transfer heat quickly

Copper cannot displace zinc from its salt solution.

In displacement reaction,

More reactive metals displace less reactive metals from their compounds

Here, Zinc is more reactive metal than Copper

Thus, Copper cannot displace Zinc from its salt solution

Copper + Zinc Sulphate  → No displacement reaction

Sodium and potassium are stored in kerosene.

Sodium and potassium are the most reactive metals, and they catch fire even when exposed to small amounts of air.

To eliminate such reactions, it is stored in kerosene.

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