2. Electrons

In this section we studied PES. PES stands for photoelectron spectroscopy which is a technique used to determine the identity of an atom or molecule by measuring how difficult it is to eject all of its electrons. We learned how to graph the PES for different elements. We also learned about binding energy which is energy required to rem0oved electrons from an element. We graphed PES with binding energy on the X axis and number of electrons on the Y axis. We observed that as we moved horizontally across a row on the periodic table, from left to right, binding energy increased because the number of protons on the electrons for any given energy level increases. We also learned that as we moved vertically down a column on the periodic table, binding energy decreases because the energy level is shielding the electrons from the increasing pull of the nucleus.