The rate constant (k) of a reaction is measured at differenct temperatures (T), and the data are plotted in the given figure. The activation energy of the reaction in kJ mol^–1 is :
(R is gas constant)

The compound that has the largest H–M–H bond angle (M = N, O, S, C) is :

The correct statement about probability density (except at infinite distance from nucleus) is :

Boron and silicon of very high purity can be obtained through :