Problem from Audio Visual Focus Topic

[DTingey_1C]

How do you solve this problem, I keep getting non-whole numbers but the answer is n=6 :/.

An excited hydrogen atom emits light with a frequency of 1.14 x 1014 Hz to reach the energy level n = 4. In what principle quantum level did the electron begin?

Thank you

[SnehinRajkumar1L]

You would solve this using the delta E equation. Substitute hv (Planck's constant * frequency) for delta E and set up the other side using the difference in energy (-hR/n^2-(-hR)/n^2). Plug in the appropriate numbers and solve. Don't forget to inverse and square root properly and you should get the right answer.