What occurs when an excited electron returns to its ground state?

the nucleus decomposes and emits nuclear energy

energy is emitted as photons of light

the electron combines with a proton in a chemical reaction

the electron is available to bond with other atoms

A

the nucleus decomposes and emits nuclear energy

c is having 4 valence electrons and is bonded to three hydrogens and one sulphur atom, therefore, the number of bond pair is equal to four. as all the valence electrons are used in forming the bonds so, there is no lone pair left on carbon.

s is having 6 valence electrons and is bonded to one other sulfur atom and one carbon atom, therefore, the number of bond pair is equal to 2. as only two valence electrons are used in forming the bonds so, four electrons are left. therefore, two lone pairs are present on s.