Compute each part of following problem:
Problem: Suppose we somehow knock out an electron from an atom. The energy level of the electron is -12.5 keV. Another electron in that atom makes a transition from its level at -1.8 keV to that empty level and emits a photon.
Part A: Find the energy (keV) of the emitted photon.
Part B: Find the wavelength (nm) of the photon. This is how x rays are produced in commercial instruments. A beam of high-energy electrons are directed at a target where they knock electrons out of atoms. Other electrons in the atoms make transitions to these empty levels, emitting photons.
Please keep it short and simple and please no copy and paste. Thank you.