NSO Level 1- Science Olympiad (SOF) Class 8: Questions 716 - 718 of 1175

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Question 716

Question

MCQ▾

Harsh was doing experiment in the science lab. The steps of procedure are given here.

i) He took a test tube and put 3 - 4 pellets of sodium hydroxide in it.

ii) Added 5 ml water in it and dissolved the pellets in it.

iii) Added some pieces of aluminium foil in the solution.

iv) Brought a lighted match stick near the mouth of the test tubes

He observed that the match stick burnt with a pop sound.

The conclusion is aluminium reacts with sodium hydroxide releasing hydrogen gas. Which property of metals is proved here?

Choices

Choice (4)Response

a.

Metals react with sodium hydroxide to form hydrogen gas

b.

Metals react with acids to form hydrogen gas

c.

Non-metals react with bases to form hydrogen gas.

d.

Metals react with bases to form hydrogen gas

Question 717

Question

MCQ▾

Sound is produced in explosion. The reason is

Choices

Choice (4)Response

a.

The hot gases expand rapidly and cause explosion

b.

Explosion is a rapid reaction where heat light and sound are produced

c.

The gases produced on burning are heated by the heat evolved in the reaction.

d.

All a., b. and c. are correct

Question 718

Question

MCQ▾

Number of ova produced by ovary at a time is

Choices

Choice (4)Response

a.

40 million to 1.2 billion

b.

10000 to 100000

c.

1

d.

100 to 1000

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