The radius of the second Bohr orbit, in terms of the Bohr radius, a₀, in Li²⁺ is :

A metal (A) on heating in nitrogen gas gives compound B. B on treatment with H₂O gives a colourless gas which when passed through CuSO₄ solution gives a dark blue-violet coloured solution. A and B respectively, are :

Consider the following plots of rate constant versus $${1 \over T}$$ for four different reactions. Which of the following orders is correct for the activation energies of these reactions?

Let ƒ(x) be a polynomial of degree 3 such that ƒ(–1) = 10, ƒ(1) = –6, ƒ(x) has a critical point at x = –1 and ƒ'(x) has a critical point at x = 1. Then ƒ(x) has a local minima at x = _______.