Unit 2: S-Block Elements

31. The color of the flame produced by burning lithium salts is:

a) Green
b) Red
c) Blue
d) Yellow
Answer: b) Red

32. The s-block element that is the hardest among all the alkali metals is:

a) Lithium
b) Sodium
c) Potassium
d) Rubidium
Answer: a) Lithium

33. Which s-block metal is used in the extraction of titanium from its ore?

a) Sodium
b) Calcium
c) Magnesium
d) Potassium
Answer: c) Magnesium

34. The density of alkali metals:

a) Increases down the group
b) Decreases down the group
c) Remains constant
d) Increases up the group
Answer: a) Increases down the group

35. The general formula for the hydroxides of alkali metals is:

a) M(OH)₂
b) M₂(OH)
c) M(OH)
d) M₂O
Answer: c) M(OH)

36. The reactivity of which of the following s-block elements is most similar to that of lithium?

a) Sodium
b) Potassium
c) Calcium
d) Magnesium
Answer: d) Magnesium

37. Which s-block metal is commonly used in making glass and ceramics?

a) Calcium
b) Magnesium
c) Sodium
d) Potassium
Answer: c) Sodium

38. The formation of which of the following compounds is a characteristic reaction of alkali metals?

a) Metal chlorides
b) Metal oxides
c) Metal nitrates
d) Metal carbonates
Answer: a) Metal chlorides

39. The s-block element used in making strong and lightweight alloys is:

a) Calcium
b) Magnesium
c) Sodium
d) Lithium
Answer: b) Magnesium

40. The basicity of oxides of alkaline earth metals generally:

a) Increases down the group
b) Decreases down the group
c) Remains constant
d) Increases up the group
Answer: a) Increases down the group