Mesityl oxide is a common name of :

Which of the following is an aromatic compound?

A central atom in a molecule has two lone pairs of electrons and forms three single bonds. The shape of this molecule is :

Given below are two statements :

Statement I : Retardation factor (R_f) can be measured in meter/centimeter.

Statement II : R_f value of a compound remains constant in all solvents.

Choose the most appropriate answer from the options given below :