the situation in which then excited state i.e. metastable state contains more number of electrons than the ground is called

Explanation

Of the listed options, only c. Population inversion accurately describes the situation where an excited state (metastable state) contains more electrons than the ground state.Here's why:Ionized state: This refers to an atom or molecule that has lost one or more electrons, resulting in a positive charge. While an ionized state can be considered an excited state due to its higher energy level compared to the ground state, it doesn't involve a higher population in the excited state compared to the ground state.Stimulations: This is a general term for the process by which an atom or molecule absorbs energy and transitions to a higher energy level. It doesn't specifically refer to the situation where the excited state has a higher population than the ground state.Population inversion: This is the specific term used to describe the non-equilibrium condition where an excited state has a higher population of electrons compared to the ground state. This phenomenon is crucial for the operation of lasers, as it allows for stimulated emission of light.Therefore, the correct answer is c. Population inversion.