The correct option with order of melting points of the pairs (Mn, Fe), (Tc, Ru) and (Re, Os) is :

The reaction $A_2 + B_2 \rightarrow 2AB$ follows the mechanism:

$A_2 \overset{k_1}{\underset{k_{-1}}{\rightleftharpoons}} A + A$ (fast)

$A + B_2 \xrightarrow{k_2} AB + B$ (slow)

$A + B \rightarrow AB$ (fast)

The overall order of the reaction is:

If $a$₀ is denoted as the Bohr radius of hydrogen atom, then what is the de-Broglie wavelength (λ) of the electron present in the second orbit of hydrogen atom? [n : any integer]

The standard reduction potential values of some of the p-block ions are given below. Predict the one with the strongest oxidising capacity.