## Atomic Spectra [ENDORSED]

cristiancampana 2H
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Joined: Fri Sep 29, 2017 7:07 am

### Atomic Spectra

I got this one wrong in the post-assessment and was not able to solve for the second answer, only the first:
. The meter was defined in 1963 as 1,650,763.73 wavelengths of radiation emitted by krypton-86 (it has since been redefined). What is the wavelength of this krypton-86 radiation? To what region of the electromagnetic spectrum does this wavelength correspond (i.e. infrared, ultraviolet, x-ray, etc.)? What energy does one photon of this radiation have?

Chem_Mod
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### Re: Atomic Spectra

If in one meter there is 1,650,763.73 wavelengths of radiation then the wavelength of krypton 86 radiation is 1 m/1,650,763.73. Calculate this value and use it to find the frequency using $c=\lambda \times v$ and then plug v into the E=hv equation to find E.

Mishta Stanislaus 1H
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### Re: Atomic Spectra

I understand the second half of the explanation, just not the first concerning the division of one by the number of wavelengths.

Hannah Chew 2A
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### Re: Atomic Spectra  [ENDORSED]

So we want to find how long one wavelength of krypton 86 is. The problem gives that there are 1,650,763.73 wavelengths in one meter. To find how long one wavelength is, we must divide 1m by the total number of wavelengths in one meter.

An analogy is: there are 4 laps in a mile. How long is each lap? Divide 1 mile by 4 to find that each lap is .25miles. I hope this helps!