Monday, November 28, 2011
Mon-Day 2
AP Chem - welcome back from Thanksgiving break! Today we reviewed the three causes of the general trend in increasing first IE across a period of elements from left to right. We then focused on the two groups of anomalies in this IE trend: group 3A and 6A. We invoked the quantum model to see that the 3A group anomaly is due to shielding of p orbital electrons by s orbital electron of the same shell. We saw that electron-electron repulsion of paired electrons in a given orbital causes the 6A group anomaly.
Of course, these anomalies could not have been predicted, but rather, we rationalize them after the fact by using the quantum atomic model.
We then discussed "consecutive" ionization energies, and saw that each successive electron requires more energy to remove; this is so firstly because each successive electron removed is from an increasingly positive cation, which naturally has an overall stronger and stronger electrostatic attraction to any electron that is being knocked out. We saw a convenient way to use this successive ionization energy data to determine the number of valence electrons in an atom of an element.
Bio - we reviewed the big picture of this unit showing the inter-relation between photosynthesis and respiration.
We then focused on the location and reactions of the two parts of photosynthesis.
In the chloroplasts of plant and green algae cells, there are stacks of thylakoids called "grana". Each granum is loaded with chlorophylls that absorb photons of light energy. This energy drives the "light-dependent" first part of photosynthesis. The light energy is converted to the chemical bond energy in ATP. Some of this energy is used to split water molecules i.e. photolysis of water molecules, to produced oxygen (which is released/diffuses out of the chloroplast and cell) and hydrogen (which gets incorporated into glucose).
We then discussed the light-independent reactions, the synthesis of glucose, which requires the ATP/energy made during the light dependent processes in the grana. The light-independent reactions occur just outside the grana, in the cytoplasm of the chloroplast called the "stroma".
Of course, these anomalies could not have been predicted, but rather, we rationalize them after the fact by using the quantum atomic model.
We then discussed "consecutive" ionization energies, and saw that each successive electron requires more energy to remove; this is so firstly because each successive electron removed is from an increasingly positive cation, which naturally has an overall stronger and stronger electrostatic attraction to any electron that is being knocked out. We saw a convenient way to use this successive ionization energy data to determine the number of valence electrons in an atom of an element.
Bio - we reviewed the big picture of this unit showing the inter-relation between photosynthesis and respiration.
We then focused on the location and reactions of the two parts of photosynthesis.
In the chloroplasts of plant and green algae cells, there are stacks of thylakoids called "grana". Each granum is loaded with chlorophylls that absorb photons of light energy. This energy drives the "light-dependent" first part of photosynthesis. The light energy is converted to the chemical bond energy in ATP. Some of this energy is used to split water molecules i.e. photolysis of water molecules, to produced oxygen (which is released/diffuses out of the chloroplast and cell) and hydrogen (which gets incorporated into glucose).
We then discussed the light-independent reactions, the synthesis of glucose, which requires the ATP/energy made during the light dependent processes in the grana. The light-independent reactions occur just outside the grana, in the cytoplasm of the chloroplast called the "stroma".
# posted by C @ 3:35 PM 
