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An atom in an excited state has a 1.0%% chance of emitting a photon in0.10ns . What is the lifetime of the excited state?

Short Answer

Expert verified

The lifetime of the excited state is10ns.

Step by step solution

01

Given Information

We are given that atom in an excited state has a1.0%chance of emitting a photon in0.10ns. We need to find the lifetime of the excited state.

02

Simplify

We are given with P=1.0%=0.01,t=0.10ns, where Pis percentage chances of emitting photon and tis time for emitting. To find lifetime of excited state, we will use the formula, τ=1r, whereris rate decay and τis lifetime of excited state . Let this be equation1.

So we need to find rate decayr, we will use the formula , r=Pt=0.010.10ns=0.10

Now we will put it in equation 1, lifetime of excited staterole="math" localid="1650310365610" τ=1r=10.10=10ns

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The 1997Nobel Prize in physics went to Steven Chu, Claude Cohen-Tannoudji, and William Phillips for their development of techniques to slow, stop, and “trap” atoms with laser light. To see how this works, consider a beam of rubidium atoms mass1.4×10-25kg traveling at 500m/safter being evaporated out of an oven. A laser beam with a wavelength of 780nm is directed against the atoms. This is the wavelength of the 5s5ptransition in rubidium, with 5s being the ground state, so the photons in the laser beam are easily absorbed by the atoms. After an average time of 15ns, an excited atom spontaneously emits a 780nmwavelength photon and returns to the ground state.

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