Ncert solutions science class 8 Solutions for Chapter 4 materials metals and non metals

Which of the following can be beaten into thin sheets?

(a) Zinc

(b) Phosphorus

(c) Sulphur

(d) Oxygen

Which of the following is not a metal?

(a) copper

(b) sulphur

(c) aluminium

(d) iron

Q1) Which of the following can be beaten into thin sheets?

(a) Zinc (b) Phosphorus (c) Sulphur (d) Oxygen

Name the petroleum product used for surfacing of roads.

Which of the following statements is correct?

(a) All metals are ductile.

(b) All non-metals are ductile.

(c) Generally, metals are ductile.

(d) Some non-metals are ductile.

Q2) Which of the following statements is correct?

(a) All metals are ductile.

(b) All non-metals are ductile.

(c) Generally, metals are ductile.

(d) Some non-metals are ductile.

Fill in the blanks.

(a) Phosphorus is a very _________non-metal.

(b) Metals are conductors of heat and ____________ .

(c) Iron is ____________reactive than copper.

(d) Metals react with acids to produce ____________ gas.

Q3) Fill in the blanks.

(a) Phosphorus is a very __________ non-metal.

(b) Metals are ___________ conductors of heat and _____________.

(c) Iron is __________ reactive than copper.

(d) Metals react with acids to produce gas ____________.

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

(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

Q4) Mark ‘T’ if the statement is true and ‘F’ if it is false.

(a) Generally, non-metals react with acids. ( )

(b) Sodium is a very reactive metal. ( )

(c) Copper displaces zinc from zinc sulphate solution. ( )

(d) Coal can be drawn into wires. ( )

Mark ‘T’ if the statement is true and ‘F’ if it is false.

(a) Generally, non-metals react with acids. ( )

(b) Sodium is a very reactive metal. ( )

(c) Copper displaces zinc from zinc sulphate solution. ( )

(d) Coal can be drawn into wires. ( )

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

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

Some properties are listed in the following table. Distinguish between metals and non-metals on the basis of these properties.

Q5) Some properties are listed in the following Table. Distinguish between metals and non-metals on the basis of these properties.

Q6) Give reasons for the following

a) Aluminium foils are used to wrap food items.

b) Immersion rods for heating liquids are made up of metallic substances.

c) Copper cannot displace zinc from its salt solution.

d) Sodium and potassium are stored in kerosene.

Give reasons for the following.

(a) Aluminium foils are used to wrap food items.

(b) Immersion rods for heating liquids are made up of metallic substances.

(c) Copper cannot displace zinc from its salt solution.

(d) Sodium and potassium are stored in kerosene

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

Q7) Can you store the lemon pickle in an aluminum utensil? Explain.

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

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

Q8) In the following Table some substances are given in Column I. In Column II some uses are given. Match the items in column I with those in Column II.

Which of the following reacts with cold water vigorously?

(a) carbon

(b) sodium

(c) magnesium

(d) sulphur

What happens when

(a) Dilute sulphuric acid is poured on a copper plate?

(b) Iron nails are placed in a copper sulphate solution?

Write word equations of the reactions involved.

Q9) What happens when

(a) Dilute sulphuric acid is poured on a copper plate?

(b) Iron nails are placed in a copper sulfate solution?

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

Q10) Saloni 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.

Saloni 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.

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

One day Reeta went to a jeweller’s shop with her mother. Her mother gave 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?

Q11) One day Reeta went to a jeweler’s shop with her mother. Her mother gave old gold jewelry to the goldsmith to polish.

The next day when they brought the jewelry back, they found that there was a slight loss in its weight. Can you suggest a reason for the loss of weight?

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 nonmetal.

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

turning in it?

Why are bells made of metals?

Rohit took with him some nylon ropes, when he was going for rock climbing. Can you tell why he selected nylon ropes instead of ropes made of cotton or jute?

Which liquid metal is used for making thermometers?

Which of the following metals can displace the other two metals from their salt solutions?

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 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.

(a) __________ is a metal.

(b) Metals are good __________ of electricity.

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

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?

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.

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.

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

Complete the crossword given in Fig. with the help of the clues.

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.