ROUTERA

Metals and Non-metals

Class 10th Science Chapter Assertion and Reason

Metals and Non-metals

  • Options:
    a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
    b) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).
    c) Assertion (A) is true, but Reason (R) is false.
    d) Assertion (A) is false, but Reason (R) is true.

 

Question 1

Assertion (A): Metals are generally good conductors of heat and electricity.
Reason (R): Metals have free electrons that facilitate the flow of energy.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Metals contain free-moving electrons that enable them to conduct heat and electricity efficiently.

Question 2

Assertion (A): Non-metals are brittle in nature.
Reason (R): Non-metals do not possess metallic bonds, which makes them strong.

  • Answer: b) Assertion (A) is true, but Reason (R) is false.
  • Explanation: Non-metals are brittle due to their molecular structure and weak intermolecular forces, not because they lack metallic bonds. They tend to break rather than deform when subjected to stress.

Question 3

Assertion (A): Sodium is a highly reactive metal.
Reason (R): Sodium has a single electron in its outermost shell, which it readily loses.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Sodium's high reactivity is due to its single valence electron, which it can easily lose to achieve a stable electronic configuration.

Question 4

Assertion (A): Metals react with acids to produce hydrogen gas.
Reason (R): This reaction occurs because metals displace hydrogen ions from acids.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: When metals react with acids, they displace hydrogen ions, leading to the production of hydrogen gas and a corresponding salt.

Question 5

Assertion (A): Non-metals have high melting and boiling points.
Reason (R): Non-metals are composed of individual molecules rather than lattice structures.

  • Answer: b) Assertion (A) is false, but Reason (R) is true.
  • Explanation: Non-metals typically have low melting and boiling points compared to metals because they exist as discrete molecules rather than in a structured lattice.

Question 6

Assertion (A): Metals are malleable and ductile.
Reason (R): Metals can be drawn into wires and shaped without breaking.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: The ability of metals to be deformed under stress without breaking makes them malleable (can be hammered into sheets) and ductile (can be drawn into wires).

Question 7

Assertion (A): Copper is used in electrical wiring.
Reason (R): Copper is a poor conductor of electricity.

  • Answer: b) Assertion (A) is true, but Reason (R) is false.
  • Explanation: Copper is an excellent conductor of electricity, which is why it is commonly used for electrical wiring.

Question 8

Assertion (A): Calcium is a metal that reacts with water.
Reason (R): Calcium forms hydrogen gas and calcium hydroxide when reacting with water.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: When calcium reacts with water, it produces hydrogen gas and calcium hydroxide, demonstrating its reactivity with water.

Question 9

Assertion (A): Metals generally form positive ions.
Reason (R): Metals lose electrons to achieve a stable electronic configuration.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Metals tend to lose electrons from their outermost shell to achieve stability, resulting in the formation of positively charged ions (cations).

Question 10

Assertion (A): The reactivity of metals increases down the group in the periodic table.
Reason (R): Atomic size increases down the group, making it easier for metals to lose electrons.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: As atomic size increases down a group, the outer electrons are further from the nucleus and are less tightly held, leading to increased reactivity of metals.

Question 11

Assertion (A): All metals are solid at room temperature.
Reason (R): Metals have strong intermolecular forces.

  • Answer: b) Assertion (A) is false, but Reason (R) is true.
  • Explanation: While most metals are solid at room temperature, mercury is a liquid. The strong metallic bonds in solids contribute to their strength, but not all metals are solid.

Question 12

Assertion (A): Iron is more reactive than copper.
Reason (R): Iron has a higher atomic number than copper.

  • Answer: b) Assertion (A) is true, but Reason (R) is false.
  • Explanation: Iron is indeed more reactive than copper, but this is due to its position in the reactivity series, not its atomic number.

Question 13

Assertion (A): Metals like aluminum and zinc are used as alloys.
Reason (R): Alloys have better physical and chemical properties than pure metals.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Alloys of metals, such as aluminum and zinc, exhibit improved properties, such as strength and resistance to corrosion, compared to their pure forms.

Question 14

Assertion (A): The reaction between metals and non-metals is usually exothermic.
Reason (R): Exothermic reactions release heat, which helps drive the reaction.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Many metal-nonmetal reactions, such as the formation of ionic compounds, are exothermic and release heat during the process.

Question 15

Assertion (A): All non-metals are poor conductors of electricity.
Reason (R): Non-metals have fewer free electrons compared to metals.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Non-metals generally lack free electrons that can move easily, resulting in their poor conductivity, with exceptions like graphite.

Question 16

Assertion (A): Metals have high density compared to non-metals.
Reason (R): The atomic structure of metals is tightly packed.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: The tightly packed atomic structure of metals contributes to their high density, whereas non-metals have lower densities due to their more spread-out atomic arrangements.

Question 17

Assertion (A): Gold is a non-reactive metal.
Reason (R): Gold does not readily react with oxygen or acids.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Gold's resistance to oxidation and reaction with acids (except for aqua regia) makes it a non-reactive metal, which is why it is used in jewelry.

Question 18

Assertion (A): Magnesium can displace zinc from its salt solution.
Reason (R): Magnesium is more reactive than zinc.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: Since magnesium is more reactive than zinc, it can displace zinc from its salt solutions, demonstrating its higher reactivity.

Question 19

Assertion (A): Sodium metal is stored under oil.
Reason (R): Sodium reacts vigorously with water and air.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: To prevent sodium from reacting with moisture in the air and water, it is stored under oil, ensuring its stability.

Question 20

Assertion (A): Metals have high melting and boiling points.
Reason (R): Metallic bonding is strong due to the attraction between positive ions and delocalized electrons.

  • Answer: a) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
  • Explanation: The strong metallic bonds that hold the metal atoms together require significant energy to break, resulting in high melting and boiling points.