In which of the following pairs, both the species are not isostructural?

1. \(\mathrm{SiCl}_4, \mathrm{PCl}_4^{+}\)
2. Diamond, silicon carbide
3. \(\mathrm{NH}_3, \mathrm{PH}_3\)
4. \(\mathrm{XeF}_4, \mathrm{XeO}_4\)
 

The stability of +1 oxidation state among Al, Ga, In and Tl increases in the sequence?
1. Ga < ln < Al < Tl
2. Al < Ga < ln < Tl
3. Tl < ln < Ga < Al
4. ln < Tl < Ga < Al

A compound among the following having a similar structure to graphite is:

1. B
2. B₄C
3. B₂H₆
4. BN

Which of these is not a monomer for a high molecular mass silicone polymer?

The basic structural unit of silicates is:

1. SiO₄^4–

2. SiO₃^2–

3. SiO₄^2–

4. SiO

A compound among the following that is least likely to behave as a Lewis base is:

Which of the following oxide is amphoteric?

1. CO₂ 

2. SnO₂

3. CaO 

4. SiO₂

Which of the following statements is incorrect?