CBSE Class 8 Science Metals and Non Metals Worksheet Set 03

b) Sodium is stored in kerosene.

 

METALS AND NON-METALS

Question. 1. Rusting of iron can be prevented by :-
(a) Alloying
(b) Painting
(c) Galvaning
(d) All of these
Answer: D

Question. 2. Which of the following is a good conductors of heat and electricity ?
(a) Graphite
(b) Oxygen
(c) Chlorine
(d) Nitrogen
Answer: A

Question. 3. Metals are :-
(a) Malleable
(b) Ductile
(c) None
(d) Both
Answer: D

Question. 4. Metals can be obtained economically from:-
(a) Minerals
(b) Ores
(c) Earth's crust
(d) None
Answer: B

Question. 5. Which of the following have low melting and boiling points ?
(a) Phosphorus
(b) Sodium
(c) Iron
(d) (A) and (B)
Answer: D

Question. 6. Which of the following metals catch fire on reaction with water ?
(a) Sodium
(b) Potassium
(c) Magnesium
(d) (A) and (B)
Answer: D

Question. 7. A metal, which forms a protective layer of its oxide on reaction with water, on its surface is :-
(a) Sodium
(b) Aluminium
(c) Potassium
(d) Magnesium
Answer: B

Question. 8. Reactivity series gives :-
(a) Arrangement of metals in the order of decreasing reactivity
(b) Arrangement of non-metals in the order of decreasing reactivity
(c) Arrangement of metals in the order of increasing reactivity
(d) Arrangement of non-metals in the order of increasing reactivity
Answer: A

Question. 9. Metals like gold, platinum which do not easily react are called :-
(a) Active metals
(b) Dull metals
(c) Noble metals
(d) Bright metals
Answer: C

Question. 10. When \( MgO \) is dissolved in water, \( Mg(OH)_{2} \) is obtained. A red litmus paper dipped in this solution turns blue, this shows that the solution is ............ in nature :-
(a) Acidic
(b) Neutral
(c) Alkaline
(d) Reactive
Answer: A

Question. 11. Calgon is a substance which is used to remove the hardness of water. The formula of calgon is :-
(a) \( Na_{2}[Na_{4}(PO_{3})_{6}] \)
(b) \( Na_{2}Al_{2}Si_{2}O_{8} \)
(c) \( FeSO_{4}(NH_{4})_{2} \cdot SO_{4} \cdot 6H_{2}O \)
(d) \( Na_{2}S_{2}O_{3} \cdot 5H_{2}O \)
Answer: A

Question. 12. Type metal is an alloy of :-
(a) \( Pb \) and \( Sn \)
(b) \( Pb, \, Sn \) and \( Sb \)
(c) \( Cu \) and \( Zn \)
(d) \( Cu, \, Sn \) and \( Sb \)
Answer: D

Question. 13. Lightest liquid metal is :-
(a) \( Hg \)
(b) \( Cs \)
(c) \( Ga \)
(d) None of these
Answer: B

Question. 14. 90% of sun's mass is :-
(a) \( He \)
(b) \( H_{2} \)
(c) \( O_{2} \)
(d) \( Ar \)
Answer: B

Question. 15. Carnallite \( (KCl \cdot MgCl_{2} \cdot 6H_{2}O) \) is an ore of :-
(a) Chlorine
(b) Iodine
(c) Astatine
(d) Bromine
Answer: D

Question. 16. Magnetite is an oxide of metal X. The metal is :-
(a) \( Mn \)
(b) \( Mg \)
(c) \( Fe \)
(d) \( Cu \)
Answer: C

Question. 17. Hoope's process is used for the purification of :-
(a) \( Cu \)
(b) \( Fe \)
(c) \( Al \)
(d) \( At \)
Answer: C

Question. 18. Mercury is also called :-
(a) Liquid gold
(b) Liquid copper
(c) Liquid silver
(d) None of these
Answer: C

Question. 19. Nitric acid can be prepared by which of the following method ?
(a) Birkeland - eyde process
(b) Ostwald process
(c) Contact process
(d) (A) & (B) both
Answer: D

Question. 20. Which of the following is/are used as bleaching agent ?
(a) \( SO_{2} \)
(b) \( H_{2}S \)
(c) \( Cl_{2} \)
(d) All
Answer: D

Question. 21. Which of the following element is not found in free state in the nature ?
(a) Silver
(b) Copper
(c) Sodium
(d) Gold
Answer: C

Question. 22. When magma cools below the surface of the earth, the granite is formed which is used in buildings. It mainly consists of :-
(a) Quartz and haematite
(b) Quartz and felspar
(c) Bauxite and calcamine
(d) Felspar and silver glance
Answer: B

Question. 23. Minerals generally have the following characteristics :-
(a) They occur naturally
(b) They have characteristics chemical composition
(c) They do not have specific chemical properties
(d) They do not have a specific chemical composition
(A) (a) and (b)
(B) (a) and (c)
(C) (c) and (d)
(D) (a) and (d)
Answer: A

Question. 24. The percentage of gold present in 20 carat gold is :-
(a) 83.33
(b) 100
(c) 50
(d) 73.3
Answer: A

Question. 25. Which of the following elements is non-metal ?
(a) \( Na \)
(b) \( Fe \)
(c) \( Cu \)
(d) \( S \)
Answer: D