Monday, September 29, 2008
Mon-Day 2
AP Chem- we looked at two important exceptions (sometimes tested on the AP exam) to the Aufbau Principle: the ground state electron configurations of Cr and Cu. We saw that electron-electron repulsion was significantly lowered by having an electron (that would otherwise pair up in the 4s orbital) in the last unoccupied 3d orbital creating a symmetric distribution of evenly spaced electrons (on average) that CAUSES the electrons to be (on average) farther apart than they would be (with 4s2 3d4 or, in Cu, with 4s2 3d9). This causes a NET lowering of potential energy given that the 3d and 4s energy sublevels are ALMOST equal to begin with (so it does not take much energy at all to bring the 4s electron that was going to be paired up to the 3d sublevel).
We then reviewed paramagnetic and diamagnetic calculations based on orbital diagrams; we also saw the logic of the ordering of energy sublevels by looking at the SUM of the n + l quantum numbers and seeing that, if there is a tie, the lower energy sublevel is ALWAYS the one with the lowest or lower principal quantum number, n.
Bio 6- we took our Biochemistry exam today. I'll return them to you on Friday, after makeups have been taken.
Bio 7/8 - we took our Biochemistry exam today. I'll return them to you on Friday, after makeups have been taken. We discussed some enzyme lab questions and did some more acid/base data gathering before the fire drill.
We then reviewed paramagnetic and diamagnetic calculations based on orbital diagrams; we also saw the logic of the ordering of energy sublevels by looking at the SUM of the n + l quantum numbers and seeing that, if there is a tie, the lower energy sublevel is ALWAYS the one with the lowest or lower principal quantum number, n.
Bio 6- we took our Biochemistry exam today. I'll return them to you on Friday, after makeups have been taken.
Bio 7/8 - we took our Biochemistry exam today. I'll return them to you on Friday, after makeups have been taken. We discussed some enzyme lab questions and did some more acid/base data gathering before the fire drill.
# posted by C @ 2:19 PM 
