NCERT Class VIII Science Solutions: Chapter 4-Materials: Metals and Non-Metals Part 1

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Question 1:

Which of the following can be beaten into thin sheets?

  1. Zinc

  2. Phosphorus

  3. Sulphur

  4. Oxygen

Answer:

A. Zinc

As Zinc is a metal and metal has property of malleability (Can be converted in sheet by beating). Rest of these are non-metals.

Image result for zinc

Result for Zinc

Question 2:

Which of the following statements is correct?

  1. All metals are ductile.

  2. All non-metals are ductile.

  3. Generally, metals are ductile.

  4. Some non-metals are ductile.

Answer:

C. Generally, metals are ductile.

Mercury (metal) is liquid at room temperature and cannot be drawn into wires. Therefore, it is non-ductile. So the option (a) is incorrect. Not a single non-metal is ductile, so option (b) and (d) are incorrect.

Image result for metals are ductile.

Metals Are Ductile

Question 3:

Fill in the blanks:

  1. Phosphorus is very ___________ non-metal.

  2. Metals are ___________ conductors of heat and ___________.

  3. Iron is ___________ reactive than copper.

  4. Metals react with acids to produce ___________ gas.

Answer:

  1. Phosphorus is very reactive non-metal.

  2. Metals are good conductors of heat and electricity.

  3. Iron is more reactive than copper.

  4. Metals react with acids to produce Hydrogen gas.

Question 4:

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

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

  2. Sodium is a very reactive metal. ( )

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

  4. Coal can be drawn into wires. ( )

Answer:

  1. Generally, non-metals react with acids. (False)

  2. Generally, metals react with acids and release gas.

  3. Sodium is a very reactive metal. (True)

  4. Sodium, Potassium, Calcium etc., are very reactive metals.

  5. Copper displaces zinc from zinc sulphate solution. (False)

  6. The reactivity of zinc is higher than copper. So, copper cannot displace zinc from zinc sulphate solution.

  7. Coal can be drawn into wires. (False)

  8. Coal is a non-metal, so it is non ductile.

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