Tuesday, December 1, 2009
Tues-Day 2
Bio 3/6- We reviewed the main purposes, locations, and results of the light dependent and light-independent reactions of photosynthesis and showed how they are related to the overall production of glucose.
We then analyzed the photosynthesis equation in order to INFER five factors that can influence/affect the rate of photosynthesis. From the equation, we saw that the concentrations of carbon dioxide and water (the REACTANTS/ingredients for photosynthesis) naturally affect the rate of photosynthesis because these are the substances that are actually being reacted! We saw that LIGHT INTENSITY/brightness/(number of photons hitting the grana/chlorophyll per second) can influence the rate of photosynthesis because the light is THE original source of energy that is converted to the chemical bond energy in ATP, needed to power the Calvin cycle/photosynthesis of glucose. We further saw that anything that affects ENZYME activity/shape/function will automatically affect the rate of photosynthesis because the reactions involved are ALL controlled/helped/aided by enzymes; therefore, TEMPERATURE and pH of the environment will affect the rate of photosynthesis. Lastly, we saw that, because chlorophylls are necessary to absorb the light energy for conversion to the energy in ATP, anything that affects the amount and types of chlorophylls can affect the rate of photosynthesis.
AP Chem- Today, for most of you, was your introduction to truly UNDERSTANDING chemistry; it can actually make sense now!
We began the logical explanation of ALL atomic periodic trends and most chemical phenomena by defining and applying THREE FACTORS that all stem from COULOMB'S LAW.
Coulomb's Law states that electrostatic force between two particles is proportional to the quantity of charge on each particle and INVERSELY proportional to the SQUARE of the distance between the two particles. In English, the greater the number of protons, the greater the electrostatic force on an electron from these protons, and also the greater the distance between two charged particles, the LESSER the electrostatic force between them.
We applied this law to explain how increasing Zeff (effective nuclear charge, Z-S) causes a greater attraction on an electron and how an increasing number of OPEL's (OCCUPIED-by electrons-principal energy levels) will increase distance of valence electrons from the nucleus and thus decrease nuclear attraction on these electrons. We also saw that electron-electron repulsion within a given PEL/shell can cause electrons to "spread out" and increase the size of an anion.
We explained the trends in atomic radius across a period (from left to right) and down a group; we even explained the LACK of change in atomic radius across the transition metals part of a period.
We explained the trend in ionic radius for metals: ALL metal cations are SMALLER than their "parent" atoms and ALL nonmetal ANIONS are LARGER than their "parent" atoms.
We defined the term "isoelectronic" and saw how to compare the sizes of isoelectronic particles.
# posted by C @ 11:04 AM 
