The diagram shows the Maxwell–Boltzmann distribution of molecular energies for a fixed mass of gas under two different conditions, represented by Curve X and Curve Y. EaE_{\text{a}}Ea represents the activation energy of a key decomposition reaction of this gas.
Which statement is correct?
The mean kinetic energy of the molecules is lower under the conditions of Curve Y than Curve X.
The total area under Curve X is greater than that under Curve Y because Curve X has a higher peak.
Changing the conditions from Curve X to Curve Y increases the fraction of molecules with energy greater than or equal to EaE_{\text{a}}Ea.
Adding a catalyst under the conditions of Curve X shifts the molecular energy distribution curve to the position of Curve Y.