## Atomic Spectra

Posts: 32
Joined: Fri Sep 28, 2018 12:23 am

### Atomic Spectra

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?
How would you start this problem and what equation(s) would you use? Thank you.

ChathuriGunasekera1D
Posts: 78
Joined: Fri Sep 28, 2018 12:17 am

### Re: Atomic Spectra

Okay I think you would start off by dividing 1 meter by 1,650,763.73 wavelengths to get the length of one wavelength of Krypton-86. This makes sense because the units become meters/one wavelength and that's what wavelength measures.

1/1,650,763.73 = 6.058 x 10-7 m which is 605.8 nm. That is in the visible light area. From there you can use c = wavelength * v and E = hv to get energy per photon.