I have a few practice test questions that I have gotten wrong and would like to know why. (I have the answers, but not the explanations) 1. Quantum transitions that result in the characteristic sharp lines of the X ray spectrum always involve a. the inner electron shells b. electron energy levels that have the same principal quantum number c. emission of beta particles from the nucleus d. neutrons within the nucleus e. protons within the nucleus I put (b) for this answer because I thought the energy levels were related to the wavelength of the absorbed/emitted photons and spectrums depend on wavelength of radiation? Correct answer is (A) 2. Quantities that are conserved in all nuclear reactions include which of the following? I. Electric charge II. Number of nuclei III. Number of protons a. I only b. II only c. I and III only d. II and III only e. I, II, and III I picked (C) because I thought that both charge and protons (the atomic number Z) need to be conserved and must be equal on both sides of the reaction equation. Can someone please give me an explaination of why charge is conserved (I just heard it somewhere) and # of protons are not?