chem
posted by Mary .
Ionization energy is defined as the minimum energy required to remove an electron from the ground state (n0) to infinity (n∞). Determine the wavelength of radiation required to ionize the hydrogen electron from the n = 2 energy level. Calculate the energy (Joules) associated with this photon. (1 cm1 = 1.986 x 1023 J)
http://en.wikipedia.org/wiki/Rydberg_formula
I will be happy to critique your work.
You may use the value you find for R in the next problem (or the value from a text) to solve for lambda, then E = hc/lambda will calculate energy in Joules. As Bob Pursley says, post your work if you get stuck and we will help you through it. h is Planck's constant and c is the speed of light in meter/second.

(6.63e34)(3e8) / (5.444e19) = 3.634e7