Statement I Micelles are formed by surfactant molecules above the critical micellar concentration (CMC). Statement II The conductivity of a solution having surfactant molecules deceases sharply at the CMC.

Step-by-step solution

At a certain concentration surfactant molecules start to aggregate and form micelle, the concentration is called critical micellisation concentration (CMC). Aggregation of surfactant molecules (ions; RCOO ⁻ ) micelle formation cause effective fall in number of free ions to conduct electricity, thus, conductivity decreases at CMC.