Please both similarities and differences between phosphorescence and fluorescence
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The Difference Between Fluorescence & Phosphorescence:
What is Fluorescence?
Some materials absorb invisible, high-energy “black” (ultraviolet) light, use part of the energy, then emit nanoseconds later bright visible light, but only while the ultraviolet light shines on it.
What is Phosphorescence?
Phosphorescence is similar to fluorescence. Both involve absorption of energy. “Glow-in-the-dark” light (phosphorescence) is not as bright as fluorescence but lasts much longer. Phosphorescence is controlled by “forbidden” quantum physics transitions.
Quantum Physics Transitions
Quantum physics transitions are changes in molecular states made possible by energy absorption. Energy changes are quantized if they can only be absorbed or emitted in predetermined values or “quanta.” After absorption, lower energy photons (light particles) can be re-emitted.
Practical Uses
Fluorescence is utilized in medicine, while phosphorescence is used for glow-in-the-dark products.
Hobbyist Uses
Mineralogists treasure fluorescent rocks.
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Phosphorescence And Fluorescence
Source(s): https://shorte.im/bawIJ
Fluorescence and phosphorescence are both examples of photoluminescence. Fluorescence involves absorbing and releasing lower energy light almost immediately, while the light release of phosphorescence is delayed, so these materials appear to glow in the dark.
In fluorescence is caused by de-excitation of excited atoms immediately after the incident cause of the radiation . The excited energy levels in the fluorescent material are unstable and have a very short life time.
However the atoms in some substances have excited energy levels which have longer life times.(longer than 10^-8s). These are known as metastable states . It takes longer to come to the ground state. As a result the substance continues to emit light for a longer time after the removal of the source of the exciting radiation. These are known as Phosphorescent substances.
phosphorescence and fluorescence are almost same but fluorescence emit its absorbed energy as soon as when phosphorescence takes some time to emits it energy