Given below are two statements:

Statement I : All the pairs of molecules (PbO, PbO₂); (SnO, SnO₂) and (GeO, GeO₂) contain amphoteric oxides.

Statement II : AlCl₃, BH₃, BeH₂ and NO₂ all have incomplete octet.

In the light of the above statements, choose the correct option.

The correct option is: Statement I is incorrect but Statement II is correct.

Let us analyze both statements step-by-step to understand why this is the correct choice:

Analysis of Statement I:
Statement I claims that all pairs of molecules (PbO, PbO₂); (SnO, SnO₂) and (GeO, GeO₂) contain amphoteric oxides.
Let's check the nature of each oxide:

• Lead oxides: Both PbO and PbO₂ are amphoteric oxides, reacting with both acids and bases.
• Tin oxides: Both SnO and SnO₂ are amphoteric oxides, reacting with both acids and bases.
• Germanium oxides: GeO₂ is amphoteric. However, GeO (germanium(II) oxide) is classified as a distinctively acidic oxide, not amphoteric (or in some contexts, it is considered basic/acidic but not amphoteric in the standard periodic trend classifications where only the higher oxidation state oxide GeO₂ shows amphoteric character while GeO is not considered amphoteric). Therefore, not all the listed pairs contain purely amphoteric oxides, making Statement I incorrect.

Analysis of Statement II:
Statement II claims that AlCl₃, BH₃, BeH₂ and NO₂ all have incomplete octet.
Let us evaluate the valence shell electron count around the central atom for each molecule:

• AlCl₃: Aluminum (Al) is in Group 13 and has 3 valence electrons. It forms three single covalent bonds with three chlorine atoms, sharing a total of 6 electrons. Thus, its valence shell has only 6 electrons, which is less than 8 (incomplete octet).
• BH₃: Boron (B) is in Group 13 and has 3 valence electrons. It forms three covalent bonds with three hydrogen atoms, sharing a total of 6 electrons. Thus, its valence shell has only 6 electrons (incomplete octet).
• BeH₂: Beryllium (Be) is in Group 2 and has 2 valence electrons. It forms two covalent bonds with two hydrogen atoms, sharing a total of 4 electrons. Thus, its valence shell has only 4 electrons (incomplete octet).
• NO₂: Nitrogen (N) is in Group 15 and has 5 valence electrons. It forms one double bond with one oxygen atom, one coordinate/single bond with another oxygen atom, and retains a single unpaired electron. The total number of valence electrons around the nitrogen atom is 7, which is an odd number and less than 8 (incomplete octet).

Since all these molecules have fewer than 8 electrons in the valence shell of their central atom, they all indeed have an incomplete octet. Therefore, Statement II is correct.

Conclusion:
Statement I is incorrect, and Statement II is correct.