Unit 3: Group IIIA and Group IVA Elements

31. The general trend in electronegativity as you move down Group IVA is:

a) Increases
b) Decreases
c) Remains constant
d) First increases, then decreases
Answer: b) Decreases

32. The main oxide formed by silicon is:

a) SiO
b) SiO₂
c) Si₂O
d) Si₂O₃
Answer: b) SiO₂

33. The main use of boric acid is:

a) In pesticides
b) In cosmetics
c) As a food preservative
d) In glassmaking
Answer: d) In glassmaking

34. The Group IVA element that is most commonly found in the Earth’s crust is:

a) Carbon
b) Silicon
c) Tin
d) Lead
Answer: b) Silicon

35. The characteristic of Group IIIA elements that distinguishes them from other groups is:

a) Their ability to form covalent bonds
b) Their ability to form ionic bonds
c) Their tendency to form acidic oxides
d) Their tendency to form basic oxides
Answer: a) Their ability to form covalent bonds

36. The compound formed by carbon and oxygen is:

a) CO
b) CO₂
c) C₂O
d) C₂O₃
Answer: b) CO₂

37. The Group IVA element that is commonly used in electrical cables due to its high conductivity is:

a) Carbon
b) Silicon
c) Tin
d) Lead
Answer: c) Tin

38. The Group IIIA element that is a major component of the Earth’s crust and used in the manufacture of aluminum is:

a) Boron
b) Gallium
c) Aluminum
d) Indium
Answer: c) Aluminum

39. The general trend in metallic character as you move down Group IVA is:

a) Increases
b) Decreases
c) Remains constant
d) First increases, then decreases
Answer: a) Increases

40. The Group IIIA element known for its use in high-temperature superconductors is:

a) Boron
b) Gallium
c) Aluminum
d) Indium
Answer: b) Gallium