Chapter 4

Which of the following is not a metal?

• (a)copper
• (b)sulphur
• (c)aluminium
• (d)iron

The substance that will be flattened on beating with a hammer is

• (a)crystal of iodine
• (b)lump of sulphur
• (c)piece of coal
• (d)zinc granule

Boojho has learnt that non-metals on beating with a hammer are generally broken into pieces. Which of the following is a non- metal?

• (a)iron nail
• (b)aluminium wire
• (c)copper plate
• (d)piece of coal

Materials which can be drawn into wires are called ductile. Which of the following is not a ductile material?

• (a)silver
• (b)copper
• (c)sulphur
• (d)aluminium

Metals are generally hard. Which of the following metals is an exception and can be cut with a knife?

• (a)iron
• (b)sodium
• (c)gold
• (d)magnesium

Metals are generally solid. Which of the following metals is in the liquid state at room temperature?

• (a)mercury
• (b)silver
• (c)aluminium
• (d)sodium

Metals generally react with dilute acids to produce hydrogen gas. Which one of the following metals does not react with dilute hydrochloric acid?

• (a)magnesium
• (b)aluminium
• (c)iron
• (d)copper M ATERIALS : METALS AND NO N- METALS 19

Which of the following reacts with cold water vigorously?

• (a)carbon
• (b)sodium
• (c)magnesium
• (d)sulphur

The metal which produces hydrogen gas on reaction with dilute hydrochloric acid as well as sodium hydroxide solution is

• (a)copper
• (b)iron
• (c)aluminium
• (d)sodium

Which of the following non-metals reacts and catches fire on exposure to air?

• (a)phosphorus
• (b)nitrogen
• (c)sulphur
• (d)hydrogen

Generally metallic oxides are basic and non-metallic oxides are acidic in nature. Solution of which of the following oxides in water will change the colour of blue litmus to red?

• (a)sulphur dioxide
• (b)magnesium oxide
• (c)iron oxide
• (d)copper oxide

Which of the following property is not responsible for copper to be used as electrical conduction wires?

• (a)ductility
• (b)colour
• (c)good conductor of electricity
• (d)it is solid

Name two soft metals which can be cut with a knife.

Which non-metal is essential for our life and all living beings inhale it during breathing?

Name two major non-metals which are present in fertilisers and enhance the growth of plants.

Which non-metal is used to disinfect water?

A purple coloured non-metal forms a brown solution in alcohol which is applied on wounds as an antiseptic. Name the non- metal.

Zinc sulphate forms a colourless solution in water. Will you observe any colour on adding copper turning in it?

E XEMPLAR PROBLEMS 19. Why are bells made of metals? 20. Which liquid metal is used for making thermometers?

Which of the following metals can displace the other two metals from their salt solutions? zinc, iron, copper

Paheli bought a statue made of copper. To her surprise it acquired a dull green coating after a couple of months. Explain the reason.

In Fig 4.1 you find that the bulb glows when an iron nail is placed between two ends of wire. Complete the following sentences on the bases of this fact. Fig 4.1

This question refers to a figure in the original PDF.

• (a)__________ is a metal.
• (b)Metals are good __________ of electricity.

If in Fig. 4.1 iron nail is replaced by a wooden stick, will the bulb glow or not? Justify your answer.

This question refers to a figure in the original PDF.

Paheli prepared a blue coloured solution of copper sulphate in beaker A and placed an iron nail in it. Boojho prepared a yellowish green solution of ferrous sulphate in beaker B and placed a copper wire in it. What changes will they observe in the two beakers after an hour? M ATERIALS : METALS AND NO N- METALS 21

A doctor prescribed a tablet to a patient suffering from iron deficiency. The tablet does not look like iron. Explain.

Match the substances in Column A with their applications given in Column B. Column A Column B (Substance) (Application) (a) oxygen

• (i)for making crackers (b) copper
• (ii)for disinfecting water (c) sulphur
• (iii)all living beings inhale during breathing (d) iron
• (iv)for making electric wires (e) chlorine (v) for making rails

Some of the following statements are incorrect. Find the incorrect statements and correct them.

• (a)The property of metals by virtue of which they can be drawn into wires is called ductility.
• (b)Metals are good conductor of electricity but poor conductor of heat.
• (c)Articles made of metals produce ringing sound when struck hard.
• (d)Oxides of non-metals and metals are acidic in nature. (e) A less reactive metal replaces a more reactive metal from its salt solution in water.

Iron is more reactive than copper. Can you write an activity to show this?

Fill in the blanks to complete the following paragraph. The name of the product formed in the reaction of sulphur and _____________ is sulphur dioxide gas. When sulphur dioxide is dissolved in_________________, sulphurous acid is formed. The sulphurous acid turns _____________ litmus paper to ____________. Generally oxides of __________ are acidic in nature. After completing the paragraph write two questions which you can raise on the basis of this information. 22 E XEMPLAR PROBLEMS

Find out the names of three metals and three non-metals from the box given as Fig 4.2. Fig 4.2

This question refers to a figure in the original PDF.

Complete the crossword given in Fig. 4.3 with the help of the clues. Fig 4.3 M ATERIALS : METALS AND NO N- METALS 23 Across 1. Which is generally hard, ductile, malleable and sonorous. 2. A metal is called so it can be drawn into wires. 3. Metal bells are used because of this property. Down 4. A metal generally used for making jewellery. 5. A metal which is liquid at room temperature. 6. A metal which reacts with acid as well as base to form hydrogen gas. 7. Substances used to enhance the growth of plants. 8. Property by virtue of which metals can be beaten into thin sheets.

This question refers to a figure in the original PDF.