Protonic acids are substances that can donate a proton (H+ ion) in aqueous solution. Let's analyze the given compounds:
(A) B(OH)3: Boron does not readily donate protons in aqueous solution, so this is not a protonic acid.
(B) PO(OH)3: Phosphorous acid (H3PO3) is a protonic acid, as it can donate protons in aqueous solution.
(C) SO(OH)2: Sulfurous acid (H2SO3) is a protonic acid, as it can donate protons in aqueous solution.
(D) SO2(OH)2: This compound, sulfuric acid (H2SO4), is a well-known strong protonic acid.
So, among the given options, (A): B(OH)3 is not a protonic acid.
Given below are two statements. 
In the light of the above statements, choose the correct answer from the options given below:
Given below are two statements:
Statement I: Nitrogen forms oxides with +1 to +5 oxidation states due to the formation of $\mathrm{p} \pi-\mathrm{p} \pi$ bond with oxygen.
Statement II: Nitrogen does not form halides with +5 oxidation state due to the absence of d-orbital in it.
In the light of the above statements, choose the correct answer from the options given below:
Given below are the pairs of group 13 elements showing their relation in terms of atomic radius. $(\mathrm{B}<\mathrm{Al}),(\mathrm{Al}<\mathrm{Ga}),(\mathrm{Ga}<\mathrm{In})$ and $(\mathrm{In}<\mathrm{Tl})$ Identify the elements present in the incorrect pair and in that pair find out the element (X) that has higher ionic radius $\left(\mathrm{M}^{3+}\right)$ than the other one. The atomic number of the element (X) is
