### Hydrogen Atom / Quantum Level

Posted:

**Sun Oct 11, 2015 7:31 pm**"An excited hydrogen atom emits light with the frequency of 1.14 x 10^14 Hz to reach the energy level for which n=4. In what principal quantum level did the electron begin?"

How do I go about solving this problem? I am kind of confused on which equation(s) to use.

How do I go about solving this problem? I am kind of confused on which equation(s) to use.