Question

• Multiple choice questions?
Phosphorescence lifetimes are
(a) shorter than fluorescence lifetimes
(c) longer than fluorescence lifetimes
() decreased by intersytem crossing
(d) measured using the heavy atom ette​

Answer 1

Answer- longer than fluorescence lifetimes

hope it helped you

Answer 2

Phosphorescence lifetimes are longer than fluorescence lifetimes (Option - c)

• Fluorescence has a nanoseconds lifetime whereas Phosphorescence lasts for microseconds.
• A Phosphorescent object absorbs light at a lower wavelength and reemits it at a longer wavelength.
• A Phosphorescent object does not directly absorb and emit as in the case of Fluorescence material but rather shows an afterglow even if the radiation source is removed.
• Phosphorescence involves the radiation or energy released as Phosphorescence when the electron returns back to its ground state from its triplet-excited state.
• Fluorescence involves the energy released when the electron returns to its ground state from its singlet-excited state.
• In Singlet excited state, the electron has the same spin as the ground paired electron.
• In Triplet excited state, the excited electron has the same spin as the unpaired ground electron.