1. The Beer-Bouger-Lambert Law and  max The Beer’s law: At a given the proportion of light absorbed by a transparent medium is independent of the intensity of the incident light and is proportional to the number of absorbing molecules through which the light passes. I 0 is the intensity of incident light I is the intensity of transmitted light k is the absorption coefficient l is the path length through the sample  is molar extinction coefficient or molar absorptivity c is the concentration in mol/L So k ≈ 2.303  c

2. Changes of Absorption Maxima

3. In-phase overlap region of AOs = bonding MO Out-of-phase overlap region of AOs (nodal plane) = antibonding MO AOs being combined must have similar energy and the same symmetry with respect to the internuclear axis

4.  = resonance energy; it becomes 0 if  E A is big S = overlap integral that typically is about 0.2 E +- = (E A +-  )/(1+-S) Linear Combination of AOs (LCAO)

5. g = even (gerade) and u = odd (ungerade) with regard to inverion

7. Penta-1,3-diene in heptane

8. Absorption of alkenes

11. Absorption of isolated chromophores