1. The problem statement, all variables and given/known data Although not a computational problem, I still have difficulties understanding emission of characteristic X-rays. Can someone please clear up my confusions about the topic? Here's where I'm stuck, with two texts as an example: Source for the above: http://hyperphysics.phy-astr.gsu.edu/hbase/quantum/xrayc.html Following this explanation, let's say we shoot out an electron from the K-shell, and an electron from the L-shell fills its place. The X-ray that will then be emitted will be of equivalent energy size as the difference between binding energies of the K-shell and L-shell of the atom. However, look at the following text: Source: https://www.bruker.com/products/x-r...ntal-analysis/handheld-xrf/how-xrf-works.html Here confusion begins. How can an electron have a higher binding energy if it is further away from the nucleus? Looking at this table, I can't understand how an electron further away from the nucleus can have higher binding energy: http://xdb.lbl.gov/Section1/Table_1-1a.htm My question is this: what type of difference of energy is an x-ray made of? The difference between the shells or the difference in the energy state of an electron? Hope my confusion made sense. P.S. Not used the template for posting assignment, since this is not a computational problem.