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O/L 2021 Science MCQ paperEnglish medium

Category :

O/L

Subject :

Science

Year :

2021

Medium :

English medium

Question Number :

30

Time Passed :

2h

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30. when thin iron wool is heated, it instantly burns. but though an iron nail till red hot, it does not undergo a considerable change. what conclusion can be drawn from these observations?

(1)

iron wool acts as a catalyst.

(2)

iron wool and iron nail undergo reactions different from each other.

(3)

the composition of iron nail and iron wool is different from each other.

(4)

the rate of reaction depends on the physical nature of the reactants.