11. Which element is a member of Group IIIA?

a) Carbon
b) Nitrogen
c) Aluminum
d) Oxygen
Answer: c) Aluminum

12. The common oxidation state of Group IIIA elements is:

a) +1
b) +2
c) +3
d) +4
Answer: c) +3

13. Which of the following is the lightest element in Group IVA?

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

14. The main oxidation state of Group IVA elements is:

a) +2
b) +3
c) +4
d) +5
Answer: c) +4

15. Which element in Group IIIA is commonly used in the production of alloys and in the manufacturing of cans?

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

16. The element in Group IVA that is widely used in the semiconductor industry is:

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

17. Which of the following is a characteristic property of Group IIIA elements?

a) High ionization energies
b) Forming amphoteric oxides
c) Forming acidic oxides
d) Having a +3 oxidation state
Answer: d) Having a +3 oxidation state

18. The primary use of boron compounds in industry is:

a) As a cleaning agent
b) In semiconductors
c) In glassmaking
d) As a fuel
Answer: c) In glassmaking

19. The trend in atomic radius as you move down Group IVA is:

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

20. The common allotropes of carbon include:

a) Diamond and graphite
b) Diamond and silicon
c) Graphite and silicon
d) Graphene and boron
Answer: a) Diamond and graphite