When a molecule absorbs a photon,the molecule is promoted to an excited state,M^*.The rate at which M^* is created is proportional to the concentration of M.There are three pathways that M^* may take to return to the ground state.Which statement below is INCORRECT for these three pathways. A)The rate at which the excited state returns to the ground state is independent of the pathway to the ground state and the concentration of excited state molecules. B)The three possible pathways to return to the ground state are emission,deactivation,and quenching. C)Quenching occurs when a second molecule,the quencher Q,collides with M^* to return M^* to the ground state.M^* + Q → M + Q^* D)Deactivation returns M^* to the ground state by colliding with other molecules and releasing energy in the form of heat.M^* → M + heat E)Emission returns M^* to the ground state by emitting a photon.M^* → M + hv.

Question

Quizplus · Accepted Answer

The statement "The rate at which the excited state returns to the ground state is independent of the pathway to the ground state and the concentration of excited state molecules" is incorrect because the rate at which the excited state returns to the ground state is dependent on the pathway taken and the concentration of excited state molecules. For example, emission is a faster pathway compared to deactivation, and quenching is a pathway where the excited state is lost without returning to the ground state, so the rate would be different for each pathway.

When a Molecule Absorbs a Photon,the Molecule Is Promoted to an Excited