Materials: Metals and Non-Metals

Q23. What is malleability?

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

Q24. What is ductility?

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

Q25. Name the product formed in the reaction of sulphur and oxygen.

Ans. The name of the product formed in the reaction of sulphur and oxygen is sulphur dioxide gas.

Q26. What is the nature of the oxide formed by sulphur?

Ans. It is acidic in nature. Generally, oxides of non-metals are acidic in nature.

Q27. What are metalloids?

Ans. Elements which possess characters of both metals and non-metals are called metalloids.

Q28. What type of oxides is formed by metals?
Or
What is the nature of oxides of metals?
Or
What type of oxides is formed when metals combine with oxygen?

Ans. On burning, metals react with oxygen to produce metal oxides which are basic in nature.

Q29. Name the metal which is found in liquid state at room temperature.

Ans. Mercury is the only metal which is found in liquid state at room temperature.

Q30. Is rust acidic, basic or neutral in nature?

Ans. Rust i.e. Iron oxide (Fe₂O₃) is basic in nature. In general, metallic oxides are basic in nature.

Q31. What type of oxides is formed by non-metals?
Or
What is the nature of oxides of non-metals?
Or
What type of oxides is formed when non-metals combine with oxygen?

Ans. Non-metals react with oxygen to produce non- metallic oxides which are acidic in nature.

Q32. Explain why aluminium foils are used to wrap food items.

Ans.  Aluminium foils are used to wrap food items because aluminium metal is malleable. Thus, it can be beaten into thin sheets.

Q33. What are the uses of metal?

Ans. Metals are used in making machinery, automobiles, aeroplanes, trains, satellites, industrial gadgets, cooking utensils, water boilers, etc.

Q34. How metals and non-metals react with water?

Ans. Some metals react with water to produce metal hydroxides and hydrogen gas. Generally, nonmetals do not react with water.

Q35. What do you mean by displacement reaction?

Ans. In displacement reaction a more reactive metal can replace a less reactive metal, but a less reactive one cannot replace a more reactive metal.

Q36. What are the physical properties of metals?

Ans. Metals are hard, lustrous, malleable, ductile, sonorous and good conductors of heat and electricity.

Q37. Why are sodium and potassium stored in kerosene?
Or
Sodium and potassium are stored in kerosene. Give reason.

Ans. Sodium and potassium are stored in kerosene because they react vigorously with oxygen and water.

Q38. What kind of handle does screw driver have and why?

Ans. Screw driver handle is either made up of wood or plastic because they are bad conductors of heat and electricity.

Q39. Why are bells made of metal and not of wood or other material?
Or
Why are metal used for making bells?

Ans. Bells are made of metal because they are sonorous. The things made of metals produce ringing sound when struck hard.

Q40. Is there a difference in the way metals and non-metals react with acids?

Ans. Non-metals generally do not react with acids but metals react with acids and produce hydrogen gas that burns with a ‘pop’ sound.

Q41. Why immersion rods for heating liquids are made up of metallic substances?

Ans. Immersion rods for heating liquids are made up of metallic substances because metals are good conductors of heat and electricity.

Q42. When materials like coal and pencil lead are beaten, their shapes do not changes, rather break down into small pieces. Why so?

Ans. This is so because coal and pencil are non-metal and they are not malleable.