chemistry
posted by chironjit .
For the hydrogen atom where Rh=2.18*10^18 J, the wavelength of the transition from the ground state to the n=3 state is_____?

First I don't think R_{H} = 2.180E18 J.
R_{H} = 1.09737E7
1/wavelength = 1.09737E7(1/1  1/9) and solve for wavelength in meters.
If you want to use that 2.18E18 J number, that can be done this way.
delta E = 2.180E18J x (1/1  1/9)
Then E = hc/wavelength and solve for wavelength.