21. Which of the following elements in Group IIIA is known for its use in LED lights?

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

22. The group IVA element that has the highest density is:

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

23. The oxides of Group IVA elements generally exhibit which type of behavior?

a) Acidic
b) Basic
c) Amphoteric
d) Neutral
Answer: c) Amphoteric

24. Which Group IIIA element is used as a neutron absorber in nuclear reactors?

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

25. The chemical reactivity of carbon is highest in which of its forms?

a) Diamond
b) Graphite
c) Fullerenes
d) Graphene
Answer: d) Graphene

26. The primary component of most Group IVA compounds is:

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

27. Which Group IIIA element is a metalloid?

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

28. The general trend in ionization energy as you move across Group IVA from left to right is:

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

29. Which Group IIIA element is used in the production of high-purity aluminum?

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

30. The common use of silicon in technology is:

a) In batteries
b) In glassmaking
c) In solar panels
d) In synthetic rubber
Answer: c) In solar panels