Wednesday, December 23, 2009
Wednes-Day 1
Bio 3/6 - we finished up some lab discussion and then looked at/for the protozoa that live in the "gut"/intestines of termites, enabling the digestion of wood/cellulose that is ingested by the termites. This situation in which the protozoa (having a hospitable living environment) and termites (obtaining nutrients/glucose via the termite digestion of cellulose) is called a MUTUALISTIC symbiotic relationship.Have a great vacation and a Happy New Year 2010!
AP Chem- we looked at transition metal - ligand complexes, which are stable ions of transition metals that have multiple coordinate covalent bonds due to an overlap of hybridized/available d-orbitals that overlap with orbitals from the "ligands", each of which has a lone pair of electrons. These complexes often absorb light intensely in certain visible regions and thus form very deeply colored solutions.
Check Blackboard for extra help files and videos on the vacation assignment.
Have a great vacation and a Happy New Year 2010!
# posted by C @ 11:13 PM 
Tuesday, December 22, 2009
Tues-Day 2
Bio 3/6 - took the unit exam on Locomotion/Regulation via the muscular, skeletal, and integumentary systems.
AP Chem - took the Bonding I/ Molecular Geometry unit exam
AP Chem - took the Bonding I/ Molecular Geometry unit exam
# posted by C @ 10:55 PM
Monday, December 21, 2009
Mon-Day 1
Bio 3/6- we discussed the term "connective tissue" and gave examples of this tissue type that joins and supports one tissue to another.
We reviewed for tomorrow's test, going over each of the subtopics and terms in this unit on the life processes of locomotion and regulation via three organ systems: the skeletal, the muscular, and the integumentary (skin).
Get to Blackboard for more practice.
We saw the first of our presentations as a "practice" or trial run so that you can get a sense of questions to anticipate and be prepared to answer with cogent, SCIENTIFICALLY sound and reasoned answers.
Suffice is to say that the future presentations should be more detailed and ready for WHY and HOW questions.
AP Chem- we reviewed for some of the subtopics on tomorrow's test such as bond order, bond length/strength, formal charge, resonance, delocalized bonding, electronic and molecular geometry.
We then reviewed the reasoning behind ionic and covalent bonding, the particles involved and the sources of the bonds.
# posted by C @ 2:05 PM
Friday, December 18, 2009
Fri-Day 2
Bio 3/6- On Monday, hand in your unit projects; we will have one or two groups do a presentation (chosen randomly by a dice roll) while the other groups will critique/ask questions of the presenting groups. The groups that do not do a presentation on Monday will present and be critiqued at a later date.
Because our trial time has not been extensive, you should remember that you will present your short-term/preliminary results on Monday. As we continue the experiment/trial, we will have more conclusive/developed results that we can present or UPDATE later this year as you hone your scientific method skills.
Check Blackboard for practice worksheets to help you further prepare for Tuesday's test.
AP Chem- we ultimately finished the rest of the electronic and molecular geometries on our chart. We walked through the difficult "5 electron domain" molecules and ions, showing the TWO different bond angles that arise.
Go to Blackboard to view the animations and do the practice worksheets/tests that are posted.
# posted by C @ 2:11 PM
Thurs-Day 1
Bio 3/6 - worked on our muscle projects for most of the two periods and discussed some of the scientific method questions that came up: a "control group" IS a comparison group; ANY comparison group that has IDENTICAL factors/setup as the experimental group EXCEPT for ONE variable. The variable that is different can be a placebo OR a different amount or TYPE of whatever is being varied (in this case, the time of each part of the exercise).
AP Chem- we continued to develop our chart (AX4, AX3E, etc.) using VSEPR, valence shell electron pair repulsion theory and valence bond theory to determing the electronic geometry and the respective orbital hybridization required for such a geometry.
# posted by C @ 2:04 PM
Wednesday, December 16, 2009
Wednes-Day 2
Bio 3/6- we discussed skin, which along with hair and nails, makes up the integumentary system. The skin mainly functions in regulation of body temperature and immunity/protection from pathogens and harmful substances.
We discussed the mechanism by which skin regulates body temperature via sweating as signaled by the nervous system and aided by the circulatory system.
AP Chem- we further discussed our grand chart of molecular geometry, giving examples of AX3 and AX2E molecules, the latter of which led to showing how valence bond theory accounts for "delocalized" pi bonding.
We discussed said pi bonds (double overlap of p or d orbital lobes above and below the plane of the nucleus) as well as the relatively stronger (direct orbital lobe head to head overlap in the plane of the nucleus) sigma bonds.
Check out the vids and powerpoints and note supplements on Blackboard.
# posted by C @ 5:35 PM
Tuesday, December 15, 2009
Tues-Day 1
Bio 3/6 - Bring in your last unit hw so that the grade may be entered.
We compared and contrasted ligaments (bone to bone, elastic) and tendons(muscle to bone, inelastic). We reviewed the various types of joints and the movement allowed by each type of joint. We then discussed and demonstrated how antagonistic muscle pairs, via their contractions, cause bones to move in opposite directions, flexing or extending.
We discussed joint diseases: arthritis and gout. We also discussed injuries to ligaments and tendons; a torn tendon can result in swelling and inflammation called tendonitis.
We discussed the three types of muscle tissue (smooth, cardiac, and skeletal), their functions, and their locations.
You were given your 100 point unit project with which you will develop your knowledge of the skeletal and muscular systems as well as get more practice APPLYING the scientific method. This project is due on Monday and will count as a test grade.
AP Chem- we discussed dimerization of odd-electron molecules and the reasons for the energy changes that occur during dimerization.
We then began to develop our all-encompassing molecular geometry/orbital hybridization/molecular polarity chart. We introduced the concept of orbital "hybridization", which is necessary to rationalize electronic geometry via electro-electron repulsion and energy minimization.
# posted by C @ 4:15 PM
Monday, December 14, 2009
Mon-Day 2
Bio 3/6 - We discussed the various adaptations = advantageous traits! that organisms have for locomotion (and why autotrophs do not have these particular adaptations). We then focused on the human skeleton, the names of the various bones, and the types of joints/junctions that form between bones: hinge (elbow), saddle (wrist), ball-and-socket (shoulder), and gliding (hands and feet).
Tomorrow, you will start a scientific investigation that will encompass most of this unit.
AP Chem - we needed to make a dent in this unit and we did so today:
we covered the formal charge "game" and how it is used to (usually) determine the most significant (to the true structure of the molecule) of a series of resonance structures. We aim to minimize the sum of the absolute values of the formal charges and, if there is a tie, favor the structure that has the more negative formal charge on the more electronegative element/atom.
We then covered "expanded octet" molecules and "odd-electron" molecules.
During our discussion, we continued to PREVIEW the logic of ELECTRONIC geometry and how it determines MOLECULAR geometry.
# posted by C @ 10:35 AM
Thursday, December 10, 2009
Thurs-Day 1
Bio 3/6- took our unit exam on Photosynthesis and Cellular Respiration. I'll have your part I results for you on Monday.
AP Chemistry- we continued practicing Lewis structures of molecules and ions; we discussed electronic geometry and how it determines molecular geometry. There are a lot of problems/tutorials on Blackboard; start practicing now.
We began to discuss "formal charge", a game that is used to help determine the most significant of a series of resonance structures of a molecule.
AP Chemistry- we continued practicing Lewis structures of molecules and ions; we discussed electronic geometry and how it determines molecular geometry. There are a lot of problems/tutorials on Blackboard; start practicing now.
We began to discuss "formal charge", a game that is used to help determine the most significant of a series of resonance structures of a molecule.
# posted by C @ 11:05 PM
Wednesday, December 9, 2009
Wednes-Day 2
TEST SKILLS- Write out the NET equations for aerobic respiration and photosynthesis (including enzymes, chlorophyll, type of energy) IMMEDIATELY after you start the test. This way, you will KNOW the reactants and the factors that can possibly affect these reactions!!! Also write out the alcoholic fermentation and the lactic acid fermentation reactions.
Make SURE that you LABEL all diagrams BEFORE you answer the questions!
AP Chem - took the unit exam on Chemical Periodicity. It's all about Bonding, Molecular Geometry, and Intermolecular Attractions until the New Year!
# posted by C @ 1:43 PM
Tuesday, December 8, 2009
Tues-Day 1
Bio 3/6- we discussed the experimental setup that shows how aerobically respiring heterotrophs produce CO2, which increases the acidity/lowers the pH of the solution they are in, thus turning the BTB indicator from blue to yellow. (Some CO2 reacts with the water to produce carbonic acid).
However, when a photosynthetic autotroph (plant or algae) is added to the setup in the presence of light energy, the plant will consume/absorb the CO2 in the solution and perform photosynthesis, thus releasing oxygen that can be used by both the heterotroph and the plant for aerobic respiration! Because the CO2 gets removed from the solution, the BTB color turns blue due to the decrease in acidity.
AP Chem - we finished our overview of intermolecular attractions, noting the relative strength of each and the proper terms for each. Ion-dipole attractions are experienced between the ions of ionic compounds and polar solvent molecules by which the partially charged region of a polar molecule is attracted to the oppositely charged ion of the salt.
We then got into the ALL-IMPORTANT skill of PROPERLY and METHODICALLY writing/drawing the correct Lewis structure of a given molecule or ion. This is crucial to understanding the geometry of the molecule or ion and the relative polarity of the molecule.
# posted by C @ 2:24 PM
Monday, December 7, 2009
Mon-Day 2
Bio 3/6 - we reviewed the terms and processes that occur during aerobic respiration and then we looked at an experimental setup that could show, using chemical indicators, that carbon dioxide is produced via aerobic respiration.
AP Chem- We discussed periodic trends in electronegativity and related the factors that influence electronegativity to explain why metals and nonmetals always form oppositely charged ions that then form ionic bonds in a lattice of cations and anions, respectively.
We then discussed some trivial facts about various elements in the periodic table.
We then began our unit on chemical BONDING and intermolecular attractions.
We discussed the difference between a true bond and a mere intermolecular attraction and noted the different types of bonds and attractions, giving an example of each.
# posted by C @ 2:15 PM
Saturday, December 5, 2009
Fri-Day 1
Bio 3/6- GREAT NEWS!!! Due to scheduling considerations, the Photosynthesis/Cellular Respiration exam date has been changed to NEXT THURSDAY, December 10. So, the unit hw will be due on TUESDAY, December 8 (it pays to read the blog!).
We discussed the two types of anaerobic respiration/fermentation: alcohol fermentation and lactic acid fermentation. Both of these types of fermentation can extract a small amount of energy from a glucose molecule and convert it to the energy stored in 2 (TWO) ATP molecules. That's it.
We then discussed the much MORE efficient, energy-extracting form of respiration that uses oxygen in the final steps of the process: AEROBIC RESPIRATION, which generates 36 (THIRTY SIX!) ATP overall per ONE glucose molecule respired.
AP Chem- we reviewed and emphasized the importance of Zeff, PEL of the electron(s) of interest, and electron-electron repulsion in the valence shell as we explained electronegativity, typical/stable ions of a given metal or nonmetal, and successive ionization energies/predicting the number of valence electrons in an atom.
PRACTICE writing and DRAWING these explanations of periodic trends and ANY anomalies to these trends that we discussed.
There are plenty of practice problems/tests as well as very good tutorials on Blackboard.
# posted by C @ 1:17 PM
Thursday, December 3, 2009
Thurs-Day 2
We then discussed the transport of water in the xylem via capillary action, which is due to adhesion of water to the xylem walls and cohesion of water molecules to each other.
We reviewed how and why of the factors that influence the rate of photosynthesis and drew graphs of each factor as the independent variable. We even saw that color type could be used as an independent variable that influenced photosynthetic rate.
We then introduced the definition and equation for cellular respiration.
We then introduced the definition and equation for cellular respiration.
We saw that Group 6A elements ALSO have anomalous/lower than expected first IE's BUT this is NOT due to s to p shielding; we drew the orbital diagrams to show that the electron pair repulsion, which is more significant between electrons in the same orbital/region of space due to their mutual proximity, causes one of those two electrons to be more easily removed from the atom.
We then explained the trend in SUCCESSIVE ionization energies to see that when the first NON-valence electron is removed, their is a DISPROPORTIONATE increase in ionization energy required. This is because NON-valence electrons are attracted to their nucleus by a much higher Zeff and these electrons are located closer to the nucleus (lower # OPEL's) than are valence electrons. Both of these factors cause greater nuclear to electron attraction.
We then defined "electron affinity" as the energy released when a gaseous atom GAINS an electron. This is measured via a laboratory procedure in which electrons are directed at a gaseous sample of atoms and the energy change is then measured. Atoms that have high EA (electron affinity) do so because of a relatively high Zeff, few OPEL's, AND not too much electron-electron repulsion as a result of gaining the new electron.
# posted by C @ 10:55 PM
Wednes-Day 1
Bio 3/6 - We discussed the morphology/structure and functions of the parts of a typical plant leaf, showing how the various layers function individually and then work together to ensure that the plant can efficiently maintain homeostasis and perform photosynthesis.
We started a lab investigating the effect of (independent variable) varying light intensity on the (dependent variable) rate of photosynthesis as measured by the rate of production of oxygen bubbles, one of the products of photosynthesis.
We started a lab investigating the effect of (independent variable) varying light intensity on the (dependent variable) rate of photosynthesis as measured by the rate of production of oxygen bubbles, one of the products of photosynthesis.
AP Chem - Peruse (the OPPOSITE of skim) the class handout on the explanations of the periodic trends and let me know if you have any questions about them on Monday.
We continued our comparison and explanation of atomic sizes among isoelectronic species (atoms or ions) in terms of (1) Zeff , (2), # of OPEL's, (3) and electron-electron repulsion in the valence shell.
We then used those same factors to explain the Periodic Trends in First Ionization Energy.
We saw that metallic elements have low Zeff on their valence electron(s) and thus have low first IE and that nonmetallic elements have relatively high Zeff on their valence electron(s) and thus have higher first IE's.
We continued our comparison and explanation of atomic sizes among isoelectronic species (atoms or ions) in terms of (1) Zeff , (2), # of OPEL's, (3) and electron-electron repulsion in the valence shell.
We then used those same factors to explain the Periodic Trends in First Ionization Energy.
We saw that metallic elements have low Zeff on their valence electron(s) and thus have low first IE and that nonmetallic elements have relatively high Zeff on their valence electron(s) and thus have higher first IE's.
# posted by C @ 10:51 PM
Tuesday, December 1, 2009
The Periodic Table...of cupcakes
# posted by C @ 6:43 PM
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
