Science

Science

1.Brass gets discoloured in air because of the presence of which of the following gases in air?

A. Oxygen

B. Hydrogen sulphide**

C. Carbon dioxide

D. Nitrogen

2.

Which of the following is a non metal that remains liquid at room temperature?

A. Phosphorous

B. Bromine**

C. Chlorine

D. Helium

3.

Chlorophyll is a naturally occurring chelate compound in which central metal is

A. copper

B. magnesium**

C. iron

D. calcium

View Answer Discuss

4.

Which of the following is used in pencils?

A. Graphite**

B. Silicon

C. Charcoal

D. Phosphorous

View Answer Discuss

5.

Which of the following metals forms an amalgam with other metals?

A. Tin

B. Mercury**

C. Lead

D. Zinc

6.Chemical formula for water is

A. NaAlO2

B. H2O**

C. Al2O3

D. CaSiO3

Answer: Option B

7.The gas usually filled in the electric bulb is

A. nitrogen**

B. hydrogen

C. carbon dioxide

D. oxygen

Answer: Option A

8.Washing soda is the common name for

A. Sodium carbonate**

B. Calcium bicarbonate

C. Sodium bicarbonate

D. Calcium carbonate

Answer: Option A

9.

Quartz crystals normally used in quartz clocks etc. is chemically

A. silicon dioxide

B. germanium oxide

C. a mixture of germanium oxide and silicon dioxide

D. sodium silicate

Answer: Option A

10.

Which of the gas is not known as green house gas?

A. Methane

B. Nitrous oxide

C. Carbon dioxide

D. Hydrogen

Answer: Option D

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