Given below are two statements :

Statement I : The covalency of oxygen is generally two but it can exceed upto four. The oxidation state of oxygen in $\mathrm{SO}_2$ is -2 and in $\mathrm{OF}_2$ it is +2 .

Statement II : The anomalous behaviour of oxygen when compared to the other elements of group 16 is due to its small size and high electronegativity.

In the light of the above statements, choose the correct answer from the options given below

Given below are two statements :

Statement I: The second ionization enthalpy of B, Al and Ga is in the order of B > Al > Ga.

Statement II: The correct order in terms of first ionization enthalpy is Si < Ge < Pb < Sn.

In the light of the above statements, choose the correct answer from the options given below :

Consider the following reactions

$\mathrm{Na_2B_4O_7} \xrightarrow{\Delta} 2X + Y$

$\mathrm{CuSO_4} + Y \xrightarrow{\text{Non-Luminous flame}} Z + SO_3$

$2Z + 2X + \text{Carbon} \xrightarrow{\text{Luminous flame}} 2Q + \mathrm{Na_2B_4O_7} + CO$

The oxidation states of Cu in Z and Q, respectively are :

Given below are two statements :

Statement I : The increasing order of boiling point of hydrogen halides is HCl < HBr < HI < HF.

Statement II : The increasing order of melting point of hydrogen halides is HCl < HBr < HF < HI.

In the light of the above statements, choose the correct answer from the options given below :