Match the substances gives in Column A with their uses given in column B. A B i. Gold a. Thermometers ii. Iron b. Electric wires iii. Aluminium c. Wrapping foods iv. Carbon d. Jewellery v. Copper e. Machinery vi. Mercury f. Fuel

Gold is a yellow shiny metal and used to make precious ornaments or jewellery. Iron is hard, cheap and easily available, it can withstand wear and tear and used to make machines. Aluminium is cheap, light and readily available, it is also non-reactive hence used to make thin sheets used for wrapping food. Carbon compounds are used as fuel as they burn easily. Copper wires have the least resistance so do not get heated when conducting electricity making them ideal for wires. There is also little loss of current on transmission. Mercury is the only liquid metal silver in colour, it is sensitive to temperature changes so used to measure the same. A B i. Gold d. Jewellery ii. Iron e. Machinery iii. Aluminium c. Wrapping foods iv. Carbon f. Fuel v. Copper b. Electric wires vi. Mercury a. Thermometers

E M B I B E

SCIENCE TEXTBOOK FOR CLASS 8>Chapter 11 - Materials : Metals and Non-Metals>Exercises>Q 6

MEDIUM

8th Jammu and Kashmir Board

IMPORTANT

Earn 100

Give reasons for the following. Sodium and potassium are stored in kerosene.

Important Questions on Materials : Metals and Non-Metals

MEDIUM

8th Jammu and Kashmir Board

IMPORTANT

SCIENCE TEXTBOOK FOR CLASS 8>Chapter 11 - Materials : Metals and Non-Metals>Exercises>Q 7

Can you store the lemon pickle in an aluminium utensil? Explain.

MEDIUM

8th Jammu and Kashmir Board

IMPORTANT

SCIENCE TEXTBOOK FOR CLASS 8>Chapter 11 - Materials : Metals and Non-Metals>Exercises>Q 8

Match the substances gives in Column A with their uses given in column B.

A	B
i. Gold	a. Thermometers
ii. Iron	b. Electric wires
iii. Aluminium	c. Wrapping foods
iv. Carbon	d. Jewellery
v. Copper	e. Machinery
vi. Mercury	f. Fuel

MEDIUM

8th Jammu and Kashmir Board

IMPORTANT

SCIENCE TEXTBOOK FOR CLASS 8>Chapter 11 - Materials : Metals and Non-Metals>Exercises>Q 9

What happens when dilute sulphuric acid is poured on a copper plate? Write word equations of the reactions involved.

MEDIUM

8th Jammu and Kashmir Board

IMPORTANT

SCIENCE TEXTBOOK FOR CLASS 8>Chapter 11 - Materials : Metals and Non-Metals>Exercises>Q 9

What happens when iron nails are placed in copper sulphate solution? Write word equations of the reaction involved.

HARD

8th Jammu and Kashmir Board

IMPORTANT

SCIENCE TEXTBOOK FOR CLASS 8>Chapter 11 - Materials : Metals and Non-Metals>Exercises>Q 10

Sarish took a piece of burning charcoal and collected the gas evolved in a test tube.
(a) How will she find the nature of the gas?
(b) Write down word equations of all the reactions taking place in this process.

MEDIUM

8th Jammu and Kashmir Board

IMPORTANT

SCIENCE TEXTBOOK FOR CLASS 8>Chapter 11 - Materials : Metals and Non-Metals>Exercises>Q 11

One day Reeta went to a jeweller’s shop with her mother. Her mother gave an old gold jewellery to the goldsmith to polish. Next day when they brought the jewellery back, they found that there was a slight loss in its weight. Can you suggest a reason for the loss in weight?

EASY

8th Jammu and Kashmir Board

IMPORTANT

SCIENCE TEXTBOOK FOR CLASS 8>Chapter 11 - Materials : Metals and Non-Metals>Exercises>Q 12

Why phosphorus is stored in water?