## Rydberg Constant

H-Atom ($E_{n}=-\frac{hR}{n^{2}}$)

Angela Cordova 3F
Posts: 30
Joined: Fri Sep 28, 2018 12:24 am

### Rydberg Constant

I noticed there are two values that are used for the Rydberg constant (3.29x10^15 and 1.09x10^7). In which circumstances are each of them used when solving a problem?

jguiman4H
Posts: 31
Joined: Fri Sep 28, 2018 12:29 am

### Re: Rydberg Constant

The Rydberg constant is 3.29 x 1015 when using frequency = R (1/n12 - 1/n22).

Because c = wavelength x frequency, there is another form of the equation. Plugging in c/wavelength for what was frequency and rearranging the equation, we'd get: 1/wavelength = R/c x (1/n12 - 1/n22).

The R/c value in the second value is the second (albeit, modified) Rydberg constant because R/c = 3.29 x 1015/ 2.998 x 108 which gives us 1.097 x 107.

So, really there only is one Rydberg constant. The second value you said is just Rydberg's constant divided by the speed of light as used in the second form of the equation. Hope this helps!

Angela Cordova 3F
Posts: 30
Joined: Fri Sep 28, 2018 12:24 am

### Re: Rydberg Constant

Thank you so much! ^^

jguiman4H
Posts: 31
Joined: Fri Sep 28, 2018 12:29 am

No problem!