Which of the following species gives a diatomic gas with diamagnetic behaviour upon reaction with concentrated $H_2SO_4$?

Concentrated $H_2SO_4$ is not used to prepare $HBr$ from $KBr$ because it

Which of the following is a pseudohalogen analogue of an interhalogen?

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

$A$ radioactive element resembling iodine in properties is

Which of the following properties increases on going down from $F$ to $I$ in Group $17$ of the periodic table?