posted by chrisalis on .
In regards to atomic emission spectroscopy:
Explain why the intensity of the color gets brighter when the metal salt concentration is higher. Salt is any ionic compound that has positive ions(called cations) and their associated negative ions (called anions). For example, lithium nitrate is a salt as well as sodium chloride.
Explain why you see a colored flame when you burn the salt solution. That is, what is going on with the salt when it's heated to give off the color light? Which part of the salt, the metal ion or its anion, gives off the color light?
I want to gather an understanding of this, but I fear that its a bit over my head. Thanks!
Suppose we take the Na ion as an example. It has one electron in the outside shell. When anything containing the Na ion is placed in a flame, (NaCl, Na2SO4, NaBr, etc), the atom absorbs energy from the flame and the outside electron is moved to an outer energy level. That is an "excited" Na atom. In a very short time, the electron will move to a lower energy level. It will lose some of the energy when it does and the energy emitted by the excited ion is in the form of light. That is the yellow light you see when a sodium salt is placed in the flame. Why does it get more intense when the solution is more concentrated? Because more ions doing their thing gives more light and more light means higher intensity.
Okay that makes much more sense than before, lol. Thanks!!!