Class 10 Science Chapter 3 Practice Question Answers - Metals and Non-metals

Ans: ductility

Ans: no

Ans: magnesium

Ans: galvanization

Ans: Copper

Ans: Metals are generally good conductors of heat and electricity, have a metallic lustre, and are malleable and ductile. Non-metals are poor conductors, lack lustre, and are brittle.

Ans: Ionic compounds consist of positive and negative ions held together by strong electrostatic forces. It requires a considerable amount of energy to overcome these forces, leading to high melting and boiling points.

Ans: Rusting is the oxidation of iron in the presence of moisture and air, forming iron oxide. 
The chemical equation is: 4Fe + 3O₂ + 6H₂O → 4Fe(OH)₃. This process weakens the iron structure over time.

Ans: The reactivity of metals increases as we move down the reactivity series. Metals at the top are less reactive and lose electrons easily, while those at the bottom are highly reactive and tend to gain electrons.

Ans: Sodium is highly reactive and reacts vigorously with air and moisture. Keeping it immersed in kerosene oil prevents its contact with air and moisture, thus preventing rapid oxidation.

Ans:  The process of electrolytic refining of copper is as follows: 

• Electrolytic refining is a method used to clean impure copper.
• In this process, the impure copper serves as the anode, while a thin sheet of pure copper acts as the cathode.
• The electrolytic cell is filled with a solution of copper sulfate.
• When electricity flows through the cell:
  • Copper from the anode dissolves.
  • This dissolved copper is then deposited onto the cathode as pure copper.
• The impurities that do not dissolve settle at the bottom and form what is known as anode mud.

Ans:

• Metals:
  • Readily lose electrons to form positive ions (cations).
  • Good reducing agents.
  • React with acids to liberate hydrogen gas.
• Non-Metals:
  • Tend to gain electrons to form negative ions (anions).
  • Good oxidizing agents.
  • Do not react with acids to liberate hydrogen gas.

Ans:

• In a blast furnace, haematite (iron ore) is mixed with coke (carbon) and limestone (flux).
• The mixture is heated at high temperatures, and carbon monoxide reduces haematite to iron.
• The iron melts and collects at the bottom, forming pig iron.
• The impurities react with limestone to form slag, which floats on top and is removed.

Ans: 

• In the solid state, ions in ionic compounds are held in a fixed position and cannot move.
• However, in the molten state or in aqueous solutions, the ions are free to move and can carry an electric current.
• This is because the movement of ions is necessary for electrical conduction.

Ans:

• Metals like iron are used in construction, aluminum in making utensils, and copper in electrical wiring.
• Non-metals like sulfur are used in making matches, carbon in pencils, and oxygen in respiration.
• Non-metalhelium is used in filling balloons due to its low density.