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Class 8 Science MCQ Questions of Materials: Metals and Non-Metals with Answers/

Answer 1

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Practice Class 8 Science MCQ Questions chapter-wise

​​​​​1. Which of the following is a liquid at room temperature?

(a) Iron
(b) Bromine
(c) Iodine
(d) Phosphorus

2. The most reactive metal is

(a) copper
(b) silver
(c) potassium
(d) calcium

3. The metal which is liquid at room temperature is

(a) sodium
(b) bromine
(c) calcium
(d) mercury

4. Which one of the following metals is the most ductile?

(a) Aluminium
(b) Copper
(c) Silver
(d) Gold

5. Which one of the following metals is the most reactive and stored in kerosene?

(a) Iron
(b) Gold
(c) Copper
(d) Sodium

6. Name the gas that evolved when magnesium reacts with dilute hydrochloric acid

(a) Chlorine
(b) Oxygen
(c) hydrogen
(d) Nitrogen

7. The metal which is not corroded by air, water and acid is

(a) copper
(b) zinc
(c) aluminium
(d) gold

8. Metals are

(a) soft and brittle
(b) hard and solid
(c) liquid
(d) generally liquid

9. Materials having qualities of both metals and non-metals are

(a) alloys
(b) metalloids
(c) noble metals
(d) none of these

10. The metal reacting readily with cold water is:

(a) gold
(b) mercury
(c) sodium
(d) magnesium

11. The best electrical conductor is

(a) gold
(b) copper
(c) silver
(d) aluminium

12. Iron is galvanised by coating it with

(a) chromium
(b) sodium
(c) magnesium
(d) zinc

13. A mineral from which metal can be extracted on the commercial scale, economically is called

(a) ore
(b) metalloid
(e) corrosion
(d) metal

14. Which of the following is a non-metal?

(a) Aluminium
(b) Oxygen
(c) Iron
(d) Silver

15. Non-metals exist in which state?

(a) Solid
(b) Liquid
(c) Gas
(d) All of the above

16. Metal oxides are

(a) neutral
(b) basic
(c) acidic
(d) all of these

17. Which substance is used for making pencil lead?

(a) Sulphur
(b) Silicon
(c) Graphite
(d) Aluminium

18. Which non-metal is used in making glass?

(a) Graphite
(b) Sulphur
(c) Silica
(d) None of these

19. Which metal is used in wrapping materials?

(a) Aluminium
(b) Zinc
(c) Copper
(d) None of these

20. Non-metals are 

(a) react with water
(b) do not react with water
(c) both (a) and (b)
(d) none of these

21. In displacement reactions

(a) a more reactive metal displaces a less reactive metal
(b) a less reactive metal displaces a more reactive metal
(c) both (a) and (b)
(d) none of these

22. The property of metals by which they can be beaten into thin sheets is called

(a) malleability
(b) ductility
(c) conduction
(d) expansion

23. Which one of the following is a metal?

(a) C
(b) N
(c) Mg
(d) O

24. The property of metal by which it can be drawn into wires is called

(a) conductivity
(b) malleability
(c) ductility
(d) flexibility

25. Which of the following pairs of compounds undergo displacement reaction when they react with each other?

(a) Cu and AgNO₃ solution
(b) Ag and FeSO₄ solution
(c) Cu and NaCl solution
(d) Mg and NaCl solution

Answer 2

​​​​​1. Answer: (b) Bromine

Explanation: The only liquid elements at standard temperature and pressure are bromine (Br) and mercury (Hg). Although, elements caesium (Cs), rubidium (Rb), Francium (Fr) and Gallium (Ga) become liquid at or just above room temperature.

2. Answer: (c) Potassium

Explanation: Highly reactive metals (potassium, sodium) are placed at the top of the reactivity series, whereas the least reactive metals (silver, gold) are placed at the bottom of the reactivity series.

3. Answer: (d) mercury

Explanation: Mercury is the only metal that is liquid at normal temperatures.

4. Answer: (d) Gold

Explanation: Gold is the most ductile metal. A wire of about 2 km length can be drawn from one gram of gold.

5. Answer: (d) Sodium

Explanation: Potassium and sodium are kept in kerosene oil because they are highly reactive metals and react with water vapour present in the air and catches fire. So, to prevent this they are kept in kerosene oil.

6. Answer: (c) hydrogen

Explanation: When the electrons from magnesium are transferred to it hydrogen is reduced from H⁺ ion to H₂ gas.

7. Answer: (d) gold

Explanation: Metals such as gold and platinum do not corrode visible because they are unaffected by oxygen and most acids.

8. Answer: (b) hard and solid

Explanation: All metals are hard except lithium,sodium, potassium which are soft and can be cut with a knife. All metals are solid except mercury (Hg) which is a liquid metal . Metals are good conductors of electricity and good conductors of heat also.

9. Answer: (b) metalloids

Explanation: The elements boron, silicon, germanium, arsenic, antimony, and tellurium separate the metals from the nonmetals in the periodic table. These elements, called metalloids or sometimes semimetals, exhibit properties characteristic of both metals and nonmetals.

10. Answer: (c) sodium

Explanation: According to the reactivity series sodium resides in the top place in comparison to the other given metals. So it reacts easily with the cold water to form sodium hydroxide.

11. Answer: (c) silver

Explanation: Silver is the best conductor of electricity because it contains a higher number of movable atoms (free electrons). For a material to be a good conductor, the electricity passed through it must be able to move the electrons; the more free electrons in a metal, the greater its conductivity.

12. Answer: (d) zinc

Explanation: Galvanizing is a process of coating iron or steel with zinc in order to provide greater protection against corrosion for the iron or steel base.

13. Answer: (a) ore

Explanation: A mineral from which a metal can be extracted on the commercial scale economically is called ore. Ore contains metal in high quantity but it also contains impurity in it.

14. Answer: (b) Oxygen

Explanation:Oxygen is non-metal while Aluminium, Iron, and Silver are metals.

15. Answer: (d) All of the above

Explanation: Non-metals are generally solids and gases. They do not exist as liquids except bromine. Bromine is a liquid non-metal.

16. Answer: (b) basic

Explanation: If we react to metal oxides with inorganic acids they form salt and water. And we know that only acid-base reactions produce salt and water. Hence, metal oxides are basic in nature.

17. Answer: (c) Graphite

Explanation: The “lead” in a pencil isn't actually made from lead. It is made from a form of carbon called graphite. The graphite is mixed with clay and formed into long thin pencil lead.

18. Answer: (c) Silica

Explanation: Glass is made of silicon dioxide or quartz. Therefore, it is not at all a metal, it is an amorphous non-metal.

19. Answer: (a) Aluminium

Explanation: Aluminium foils are used to wrap food items. Immersion rods are made up of metallic substances.

20. Answer: (b) do not react with water

Explanation:  Non-metals do not react with water (or steam) to evolve hydrogen gas, as, non-metals give electrons to reduce the hydrogen ions of water into hydrogen gas.

21. Answer: (a) a more reactive metal displaces a less reactive metal.

Explanation:  A displacement reaction is a chemical reaction in which a more reactive element displaces a less reactive element from its compound. Both metals and non-metals take part in displacement reactions. Example: Reaction of iron nails with copper sulphate solution.

22. Answer: (a) malleability

Explanation:  Malleability is the quality of something that can be shaped into something else without breaking, as the malleability of clay. Malleability — also called plasticity — has to do with whether something can be moulded.

23. Answer: (c) Mg

Explanation:  Magnesium is a metal. It is silvery-white and very light.

24. Answer: (c) ductility

Explanation:  Ductility is the ability of a material to be drawn or plastically deformed without fracture. It is therefore an indication of how 'soft' or malleable the material is. An increase in carbon, for example, will increase the strength but decrease the ductility.

25. Answer: (a) Cu and AgNO₃ solution

Explanation: Silver nitrate and copper metal undergo a displacement reaction as copper is more reactive than silver. Hence, it displaces silver to form copper nitrate.

Cu(s)+2AgNO₃(aq) → Cu(NO₃)₂(aq)+2Ag(s)

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