Materials Metals And Non-metals(8th Grade > Chemistry ) Questions and Answers

Question 1. Calcium hydroxide is basic in nature. Identify the metal present in the compound?
  1.    Hydrogen
  2.    Oxygen
  3.    Calcium
  4.    Helium
Explanation:-
Answer: Option C. -> Calcium
:
C
Calcium hydroxide is a base. The metal in the given compound is calcium and the non metals present are hydrogen and oxygen.
Question 2. Non-metals are not good conductors of heat hence they can also be called as conductors.
  1.    True
  2.    False
  3.    Calcium
  4.    Helium
Explanation:-
Answer: Option B. -> False
:
B
Non metals are bad conductors of heat and electricity and hence they are called as insulators.
Question 3. An amphoteric oxide is an oxide that can act as either an acid or a base in a reaction.
  1.    True
  2.    False
  3.    amphoteric
  4.    neutral
Explanation:-
Answer: Option A. -> True
:
A
An amphoteric oxide is an oxide that can act both as an acid and as a base. An example is aluminum oxide, Al2O3. It reacts with acids to form the corresponding aluminum salt, and with bases to form salts called aluminates.
Question 4. Metals are generally sonorous.
  1.    True
  2.    False
Explanation:-
Answer: Option A. -> True
:
A
Metals arecapable of producing a deep or ringing sound, Thus they are said to be sonorous.
Question 5. Metals, except Al and Zn, react with oxygen to form _______ oxides.
  1.    acidic
  2.    basic
  3.    amphoteric
  4.    neutral
Explanation:-
Answer: Option B. -> basic
:
B
Most of themetals react with oxygen to form metal oxides.
For example: magnesium reacts with oxygen to form magnesium oxide. The reaction involved is:
2Mg(s)+O2(g)→2MgO(s)
The metal oxideform alkali solution when dissolved in water. This solution turns red litmus paper to blue. Hence, these metal oxides are basic in nature.
Question 6. A substance is said to be sonorous if it _________.
  1.    produces a ringing sound when beaten
  2.    conducts water through metal pipes
  3.    conducts electricity
  4.    conducts heat
Explanation:-
Answer: Option A. -> produces a ringing sound when beaten
:
A
Substances that produce a ringing sound when they are beaten are said to be sonorous. Metals are generally sonorous.
Question 7. What will be formed if you mix zinc sulphate and copper turnings?
  1.    Copper sulphate
  2.    Zinc
  3.    Copper sulphide
  4.    No reaction
Explanation:-
Answer: Option D. -> No reaction
:
D
In the reaction between zinc sulphate and copper, no products will be formed as the reaction is not possible. Zinc is more reactive than copper and hence copper will not be able to displace zinc from its salt solution.
Question 8. The property of metal by which it can be drawn into wires is called _____.
  1.    ductility
  2.    malleability
  3.    sonority
  4.    lusture
Explanation:-
Answer: Option A. -> ductility
:
A
The property of metal by which it can be drawn into wires is called ductility. Example, copper and aluminium wires are widely used.
Question 9. Which among the following non-metal combines with sodium to form common salt?
  1.    Carbon
  2.    Chlorine
  3.    Iodine
  4.    Bromine
Explanation:-
Answer: Option B. -> Chlorine
:
B
Sodium is a metal ion which combines with an ion of the non-metal chlorine(Cl) to form sodium chloride also know as the common salt.
Question 10. A reaction in which a more reactive metal replaces a less reactive metal from its salt solution is called a/an ________ reaction. 
  1.    addition
  2.    double displacement
  3.    combination
  4.    displacement
Explanation:-
Answer: Option C. -> combination
:
C
When one metal replaces another metal from its salt solution, the type of reaction is termed as adisplacement reaction.
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