Class 10 Science

Metals and Non-metals

NCERT Exemplar Problems

MCQ Part 4

Question 28: Which among the following alloys contain mercury as one of its constituents?

  1. Stainless steel
  2. Alnico
  3. Solder
  4. Zinc amalgam
    Answer: (d) Zinc amalgam

Explanation: Amalgam is a mixture of mercury and any other metal.

Question 29: Reaction between X and Y, forms compound Z. X loses electron and Y gains electron. Which of the following properties is not shown by Z?

  1. Has high melting point
  2. Has low melting point
  3. Conducts electricity in molten state
  4. Occurs as solid
    Answer: (b) Has low melting point

Explanation: Z is an ionic compound because it is formed by give and take of electrons. We know that ionic compounds are found as solid, have high melting point and conduct electricity in molten state.

Question 30: The electronic configurations of three elements X, Y and Z are X — 2, 8; Y — 2, 8, 7 and Z — 2, 8, 2. Which of the following is correct?

  1. X is a metal
  2. Y is a metal
  3. Z is a non-metal
  4. Y is a non-metal and Z is a metal
    Answer: (d) Y is a non-metal and Z is a metal

Explanation: X is noble gas because it has 8 electrons in outermost shell. Y is a non-metal because it can gain one electron to complete octet. Z is a metal because it can donate 2 electrons to complete octet.

Question 31: Although metals form basic oxides, which of the following metals form an amphoteric oxide?

  1. Na
  2. Ca
  3. Al
  4. Cu
    Answer: (c) Al

Question 32: Generally, non-metals are not conductors of electricity. Which of the following is a good conductor of electricity?

  1. Diamond
  2. Graphite
  3. Sulphur
  4. Fullerene
    Answer: (b) Graphite

Question 33: Electrical wires have a coating of an insulting material. The material, generally used is

  1. Sulphur
  2. Graphite
  3. PVC
  4. All can be used
    Answer: (c) PVC

Question 34: Which of the following non-metals is a liquid?

  1. Carbon
  2. Bromine
  3. Phosphorus
  4. Sulphur
    Answer: (b) Bromine

Question 35: Which of the following can undergo a chemical reaction?

  1. MgSO4 + Fe
  2. ZnSO4 + Fe
  3. MgSO4 + Pb
  4. CuSO4 + Fe
    Answer: (d) CuSO4 + Fe

Explanation: Iron will displace copper from copper sulphate because it is more reactive than copper.

Question 36: Which one of the following figures correctly describes the process of electrolytic refining?

exemplar mcq question 35

Answer: (c)

Explanation: Both figures (b) and (c) appear to be correct. But as per convention, anode should be shown on RHS. So, (c) is the correct answer. In both the cases, copper ions are liberating from anode and getting deposited at cathode.