Question

What is the basic difference between Fluorescence and Phosphorescence?

Answer 1

Fluorescence a transition from single exited state to ground state ; Phosphorescence triplet excited to the ground state

Explanation:

When a molecule absorbs radiation it will get excited to higher energy states. These states high spin multiplicity also. If spin multiplicity is one it is singlet, where if it is three its is called triplet.

The sketch clearly gives difference between fluorescence and phosphorescence

Fluorescence is allowed transition whereas phosphorescence is not allowed as per the selection rules

Fluorescence excited state life time is shorter, where is higher for phosphorescence