SciHawks

Bio - Our next unit on the Digestive and Endocrine Systems is covered in Chapter 35 of the text so you can start to outline those sections if you want a preview of what we cover when we return.
We spent the period reviewing the Scientific Method, showing the logical order and necessary safeguards against deception involved in the process. This method allows a person to PROPERLY and efficiently measure/investigate the relationship between two things/variables in nature that might or might not actually be related.
We also emphasized the ULTIMATE importance of reading/understanding and answering ONLY and SPECIFICALLY what is asked for in a question. Any unrelated or extraneous information will not only waste your time for no credit, but also may cause you to contradict your relevant answer, thus taking away any of your credit. So, the next time you speed through a question and ASSUME that the question is identical to something that you have seen before, REALIZE that you may be doing work for nothing. Remember, writing true statements, by themselves, is worth nothing on a test, HOWEVER, writing true statements that answer what is ASKED FOR will get you full credit.
One great reason to practice test skills is so that you do not waste your time and effort on a test.

Chem 7/8- we practiced and reviewed formula writing for binary salts, which are lattices of cations and anions held together by ionic bonds (positive attracts negative).
We also previewed some of what we will do after the break: salts that are made up of polyatomic ions as well as compounds made exclusively of NONMETALS, which are known as MOLECULES- elements or compounds in which the atoms SHARE their valence electrons to acquire a noble gas valence electron configuration.
We then finished our Alkaline Earth Metals lab, which we will write up on the second day of our return from break.

Chem 9 - we practiced and reviewed formula writing for binary salts, which are lattices of cations and anions held together by ionic bonds (positive attracts negative).
We also previewed some of what we will do after the break: salts that are made up of polyatomic ions as well as compounds made exclusively of NONMETALS, which are known as MOLECULES- elements or compounds in which the atoms SHARE their valence electrons to acquire a noble gas valence electron configuration.

Bio- we had our unit exam today;
we then updated our lab folders.
Our next unit covers the text chapter 35 on the digestive system and the endocrine (hormone) system.

Chem 7- we had our Periodic Table unit exam.
We are now prepared to start the most important unit in chemistry: Bonding and Intermolecular Attractions.

Chem 8/9- we had our Periodic Table unit exam. We then spent more time on the Alkaline Earth metals lab; we will finish that after the break.
We are now prepared to start the most important unit in chemistry: Bonding and Intermolecular Attractions.

Bio- we finished our unit review; review your notes, watch all posted Blackboard animations, and keep writing all of the relevant information that you will transfer directly from your short-term memory to your test paper as soon as the test begins. This way, you will have your own handy reference sheet for the test to make you faster and more accurate.
Since proper scientific method and graphing skills are always tested, review your notes, text, and past tests on those skills.
Good luck tomorrow! I'll be in Room 301 around 8AM. Beware, there is also a Chemistry exam tomorrow so you need to be prepared with specific questions from your studies.

Chem 7/8- we discussed salts of transition metals, noting that most transition metals CAN form more than one type of cation. Using the KNOWN nonmetal anion charge in a given formula, you can always deduce the charge on the transition metal cation that balances the negative charge from the anion(s).
We then looked at the electron configurations of the various cations of a given transition metal.
Remember, salts of transition metals form COLORED solutions; salts of representative metals e.g. NaCl form COLORLESS solutions.
ALL solutions are "clear"/transparent, whether or not they are colored.
We then did a comprehensive activity using the Reference Tables to see the periodic trends. Check your work on that, study, and good luck tomorrow!
I'm in Room 301 around 8AM tomorrow.

Chem 9- we discussed salts of transition metals, noting that most transition metals CAN form more than one type of cation. Using the KNOWN nonmetal anion charge in a given formula, you can always deduce the charge on the transition metal cation that balances the negative charge from the anion(s).
We then looked at the electron configurations of the various cations of a given transition metal.
Remember, salts of transition metals form COLORED solutions; salts of representative metals e.g. NaCl form COLORLESS solutions.
ALL solutions are "clear"/transparent, whether or not they are colored.
Check your work on the comprehensive Reference Table/Periodic trends worksheet that is posted on Blackboard, study, and good luck tomorrow!
I'm in Room 301 around 8AM tomorrow.

Bio- Reminders: we will finish our review on Wednesday and then have the unit exam on Thursday. I will hand back your graded outlines; don't forget to read them as part of your study for Thursday's exam.

Here are some of the recent cutting-edge Biology articles recently in the news:

This one is on the recent discovery of how fat is stored in adipose/fat cells, which may lead to a treatment for obesity:

http://www.sciencedaily.com/releases/2007/12/071217171416.htm

This one is on the development of LIVING CELLS from laboratory synthesized (NOT extracted from a living organism) DNA. This could be one of the most revolutionary developments EVER in Biology!

http://www.washingtonpost.com/wp-dyn/content/article/2007/12/16/AR2007121601900_pf.html

This one is on the use of a thin protein film, which coats food before deep-frying in fat in order to prevent fat seepage/soaking into the cooking food. The result is a 25% to 75% reduction in fat content of the fried food. Biochemistry, good times.

http://www.sciencedaily.com/videos/2006/0111-lowfat_fried_food.htm

As part of your review for Thursday's exam, check out the animations on Blackboard.

Today, we went over some of the unit exam objectives and we will finish going over the rest of the objectives tomorrow.

We also went over our lab, reviewing the proper terms and procedures of any scientific investigation/experiment. We identified the purpose of the experiment, the independent and dependent variables, the controlled (kept equal) variables, and the control group. Our experimental procedure had two relative groups but no control group (the group with no muscular contractions). We also decided on an appropriate graph that showed the difference between the two experimental groups.

Chem 7- We practiced figuring the correct chemical formula for each type of binary salt. Binary salts are composed of metal cations and nonmetal anions. The charge on each cation and anion determines the ratio of the cations to anions in the salt's lattice of ions.

We worked out a chart showing practically EVERY possible binary salt formula. ALWAYS check your final answer by making sure that the total positive charge from the cation or cations in the formula EQUALS the total negative charge from the anion or anions in the formula.
We gave an example of each type of salt empirical/chemical formula that can form.

We also took chemical formulas and worked backwards to get the charge of the cation and anion in the formula. Salts do not have a net charge so you will not write charges in your final formula!

Tomorrow, we will look at some transition metal salts and then review for Thursday's test.

Chem 8/9- We saw how binary salts can form from atoms of a metal and a nonmetal. When metal and nonmetal atoms collide, because the metal atom has a low Zeff on its valence electron(s) and the nonmetal atom has a high Zeff on its valence electrons, the metal will ALWAYS lose ALL of its valence electrons and the nonmetal will gain enough electrons to form a noble gas valence electron configuration. So, the metal atoms become (smaller) cations and the nonmetal atoms become (larger) anions; THEN, the cations and anions form IONIC bonds to each other in a regular geometric pattern called a LATTICE because positively charged particles (cations) attract negatively charged particles (anions).

We practiced figuring the correct chemical formula for each type of binary salt. Binary salts are composed of metal cations and nonmetal anions. The charge on each cation and anion determines the ratio of the cations to anions in the salt's lattice of ions.

We worked out a chart showing practically EVERY possible binary salt formula. ALWAYS check your final answer by making sure that the total positive charge from the cation or cations in the formula EQUALS the total negative charge from the anion or anions in the formula.
We gave an example of each type of salt empirical/chemical formula that can form.

We also took chemical formulas and worked backwards to get the charge of the cation and anion in the formula. Salts do not have a net charge so you will not write charges in your final formula!

Tomorrow, we will look at some transition metal salts and then review for Thursday's test.

Bio- UPDATE!!! OUR UNIT EXAM IS ON THURSDAY, DECEMBER 20, 2007; it covers the integumentary system/the skin, the musculo-skeletal system (muscles and bones/skeleton),and locomotion.

HW: Text Ch. 34.3 outline is due on Tuesday (tomorrow).

Today, we reviewed the functions/purposes of skin, muscles, bones, and cartilage. We further discussed the connective tissues: tendons (muscle to bone) and ligaments (bone to bone).

We further discussed and viewed the various diseases (failures to maintain homeostasis) of the skin, muscles, and bones:
skin- dermatitis (excema), melanoma/cancer...see pictures in the posted notes
muscles- muscular dystrophy, the weakening or loss of muscle tissue
ligaments and tendons: tearing of this connective tissue (sprains), tendonitis
bones: arthritis, osteoporosis, gout

Bring in Friday's lab and the completed Sports Injuries handout (check your answers on Blackboard); we will finish up the lab writeup and hand that in tomorrow.

Chem 7/8- we explained the reactivities of metals in terms of Zeff on the valence electron(s)
and the number of OPEL's.
We can use the shortcut: on the Periodic Table, the more active metal is located closer to Fr since Fr is the MOST active metal (lowest Zeff and greatest number of OPEL's cause its valence electrons to be weakly held/easily lost/"reacted), but only referring to Zeff and OPEL's will EXPLAIN why one metal is more active than another.
We also explained the reactivities of nonmetals in terms of Zeff on the valence electron(s)
and the number of OPEL's.
We can use the shortcut: on the Periodic Table, the more active metal is located closer to F since F is the MOST active nonmetal (very high Zeff (+7) and very low number of OPEL's (2) cause any electrons (from other atoms) that come near its valence shell to be strongly held/easily gained, but only referring to Zeff and OPEL's will EXPLAIN why one nonmetal is more active (gains electrons more easily) than another.
We then compared the sizes of a given metal atom to its stable typical ion. Because the metal atom LOSES electrons to become a CATION, the CATION formed has one LESS OPEL, therefore the cation is SMALLER than the atom that it was made from. This is true for ALL metal atoms that become CATIONS.
We then compared the sizes of a given NONMETAL atom to its stable typical ion. Because the nonmetal atom GAINS electrons to become an ANION, the ANION formed has the same Zeff on those new electrons, the SAME number of OPEL's (because electrons are only added to the VALENCE shell) BUT THERE IS MORE ELECTRON to ELECTRON REPULSION, which spreads out the electrons farther from each other thus making the ANION bigger than the atom from which the anion formed.
Finally, we saw the meaning of the numbers in the chemical formulas of ionic compounds/salts of metal cations with nonmetal anions. We will practice writing the correct formulas for ionic compounds/salts.

Chem 9- we explained the reactivities of metals in terms of Zeff on the valence electron(s)
and the number of OPEL's.
We can use the shortcut: on the Periodic Table, the more active metal is located closer to Fr since Fr is the MOST active metal (lowest Zeff and greatest number of OPEL's cause its valence electrons to be weakly held/easily lost/"reacted), but only referring to Zeff and OPEL's will EXPLAIN why one metal is more active than another.
We also explained the reactivities of nonmetals in terms of Zeff on the valence electron(s)
and the number of OPEL's.
We can use the shortcut: on the Periodic Table, the more active metal is located closer to F since F is the MOST active nonmetal (very high Zeff (+7) and very low number of OPEL's (2) cause any electrons (from other atoms) that come near its valence shell to be strongly held/easily gained, but only referring to Zeff and OPEL's will EXPLAIN why one nonmetal is more active (gains electrons more easily) than another.
We then compared the sizes of a given metal atom to its stable typical ion. Because the metal atom LOSES electrons to become a CATION, the CATION formed has one LESS OPEL, therefore the cation is SMALLER than the atom that it was made from. This is true for ALL metal atoms that become CATIONS.
We then compared the sizes of a given NONMETAL atom to its stable typical ion. Because the nonmetal atom GAINS electrons to become an ANION, the ANION formed has the same Zeff on those new electrons, the SAME number of OPEL's (because electrons are only added to the VALENCE shell) BUT THERE IS MORE ELECTRON to ELECTRON REPULSION, which spreads out the electrons farther from each other thus making the ANION bigger than the atom from which the anion formed.
Finally, we saw the meaning of the numbers in the chemical formulas of ionic compounds/salts of metal cations with nonmetal anions. We will practice writing the correct formulas for ionic compounds/salts.

Bio- Reminder: for hw, outline text Section 34.2, which I will collect on Monday; Section 34.3 outline will be due on Tuesday.
we discussed some of the common joints formed at various parts of the skeletal system. Different joints allow for different types/ranges of motion. For example, a ball-and-socket joint allows for rotational motion of the arms or legs whereas a hinge joint allows for movement towards and away from the body.

We then showed and discussed the purpose/function of cartilage, the supportive and flexible tissue that is found at the ends of each bone.
We discussed some of the major diseases of the skeletal system:
arthritis-inflammation of the joints, which can have various causes, genetic and environmental tendonitis- inflamed tendons, which connect bone to muscle
GOUT- the deposit of solid uric acid crystals into joints, which causes swelling (from osmosis and from other fluids) and pain
We also discussed some of the major bones of the human skeleton.

We then analyzed the three types of muscle tissue:
1. skeletal muscle, which is VOLUNTARY (you consciously decide when to contract skeletal muscles), STRIATED/STRIPED in appearance, and they each typically have more than one nucleus!
2. cardiac muscle, which is heart muscle- involuntary (your heart beats independently of your conscious decision), STRIATED/STRIPED, and very strong.
3. smooth muscle, which lines your digestive tract organs as well as your arteries- this muscle is NOT STRIPED but SMOOTH in appearance, it is INVOLUNTARY i.e. your arteries will pulse/squeeze/contract whether or not you consciously want them to.

We did a lab activity that compared the relative strength of the antagonistic muscle pair, the biceps and triceps. Muscles come in antagonistic groups such that when one of the two muscles in the group is flexing, the other is relaxing; the antagonistic muscles move the bones in opposite directions.
Your bicep is a flexor, causing your arm to move towards your body but the tricep is an extensor, causing your arm to extend away from your body.
The "Sports Injury" part of the lab will be posted this weekend. Do the lab yourself and then check your answers. We will finish up the lab on Tuesday.

Chem 7- check out Blackboard, there are a LOT of extra help files (with ANSWERS) for you to practice with over this weekend and before the exam on Thursday. I also posted the answers to the worksheets that we did during our double-periods; check your answers and ask me in class about anything that you didn't understand.
We discussed the properties of active metals, showing that Fr must be the most active metal i.e. easily loses its valence electron/becomes a cation because its valence electrons are so weakly attracted to its nucleus; this is due to the low Zeff (+1) and high number of OPEL's (7)/much electron shielding from the kernel electrons (87 protons BUT 86 shielding electrons!)
We also discussed the properties of active NONMETALS, showing that F must be the most active nonmetal i.e. easily GAINS a new valence electron / becomes an ANION because any electron that comes near its valence shell experiences a HIGH Zeff (+7) and is relatively close to the F nucleus (only 2 OPEL's, less electron shielding) so that electron will be strongly attracted to the F nucleus.
We then further discussed some general properties of the various groups of the Periodic Table.
We showed Mendeleev's criteria for the Periodic Table: arrangement of elements in order of increasing atomic mass and grouping by similar chemical properties/types of compounds formed.
This periodic table led to an anomaly involving Te and I. Though Te has a greater atomic mass than I, Mendeleev placed Te in the group before I to keep the chemical properties of both groups consistent.
Later on, this discrepancy was resolved when the elements were arranged in order of atomic number/number of PROTONS. Of course, it is the number of protons, NOT the atomic mass, that directly affects chemical properties by dictating the number of electrons and VALENCE electrons of an atom. Generally, ONLY valence electrons are lost, gained, or shared in chemical reactions.
See the summary notes on Blackboard regarding Mendeleev and the modern Periodic Table arrangement.

Chem 8/9- check out Blackboard, there are a LOT of extra help files (with ANSWERS) for you to practice with over this weekend and before the exam on Thursday. I also posted the answers to the worksheets that we did during our double-periods; check your answers and ask me in class about anything that you didn't understand.
We discussed the properties of active metals, showing that Fr must be the most active metal i.e. easily loses its valence electron/becomes a cation because its valence electrons are so weakly attracted to its nucleus; this is due to the low Zeff (+1) and high number of OPEL's (7)/much electron shielding from the kernel electrons (87 protons BUT 86 shielding electrons!)
We also discussed the properties of active NONMETALS, showing that F must be the most active nonmetal i.e. easily GAINS a new valence electron / becomes an ANION because any electron that comes near its valence shell experiences a HIGH Zeff (+7) and is relatively close to the F nucleus (only 2 OPEL's, less electron shielding) so that electron will be strongly attracted to the F nucleus.
We then further discussed some general properties of the various groups of the Periodic Table.
We showed Mendeleev's criteria for the Periodic Table: arrangement of elements in order of increasing atomic mass and grouping by similar chemical properties/types of compounds formed.
This periodic table led to an anomaly involving Te and I. Though Te has a greater atomic mass than I, Mendeleev placed Te in the group before I to keep the chemical properties of both groups consistent.
Later on, this discrepancy was resolved when the elements were arranged in order of atomic number/number of PROTONS. Of course, it is the number of protons, NOT the atomic mass, that directly affects chemical properties by dictating the number of electrons and VALENCE electrons of an atom. Generally, ONLY valence electrons are lost, gained, or shared in chemical reactions.
See the summary notes on Blackboard regarding Mendeleev and the modern Periodic Table arrangement.
We then did an important activity worksheet that gives you practice locating relevant quantitative information (electronegativity, first IE, number of valence electrons) about elements so that you can see trends in various properties/measurements across each period and down each group. Of course, all of these trends are EXPLAINED in terms of Zeff and OPEL's/electron shielding.
I saw that a LOT of you had questions about the QM electron configurations. Keep practicing drawing out the sublevels in order of increasing energy and then you will not have a problem.
For example: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 ...is MORE than you'll ever need.
I will collect this activity after we discuss it on Tuesday.

Bio- Reminder: test corrections (make SURE that you write out the full correction with explanation, drawing, equation) are due tomorrow. Advance HW notice, the outline to text section 34.2 will be due on Monday and the outline to section 34.3 will be due on TUESDAY (you may want to do both outlines over the weekend).
we discussed the life process of LOCOMOTION in both simple organisms (paramecium, amoeba) and complex organisms. Complex organisms use their musculo-skeletal systems to perform locomotion in order to:
1. seek food/nutrition/water/shelter
2. find a mate
3. evade/avoid predators or other dangers

We focused on the endoskeleton of humans which is made up of bones and cartilage.
We discussed five functions/purposes of bone e.g. support, protection, blood cell production, fat storage, and Calcium ion storage/reservoir.
We then looked at the various ranges of motion afforded by the different types of bone joints of the body.
We will look at various failures to maintain homeostasis when we see diseases of the skeletal system.

Chem 7/8- Reminder: the Periodic Table Unit homework packet is due next Tuesday, December 18. Our unit exam is on Thursday, December 20.
we explained the general trend in periodic properties of atomic size, electronegativity, and first ionization energy in terms of Zeff and OPEL's (a.k.a. the electron "shielding" effect). As you can see, ALL of these properties are based on the STRENGTH of the ATTRACTION between the valence electrons and their nucleus.
We then looked at the original Periodic Table as assembled by Mendeleev who used atomic mass as one of the criteria for ordering the elements. His other criterion was to group elements that behaved chemically similarly.
We then did a Periodic Table activity that placed elements based on their properties and atomic structures.
Download and study the explanations of the trends from today's notes and also look at the tutorial files.


Chem 9- Reminder: the Periodic Table Unit homework packet is due next Tuesday, December 18. Our unit exam is on Thursday, December 20.
we explained the general trend in periodic properties of atomic size, electronegativity, and first ionization energy in terms of Zeff and OPEL's (a.k.a. the electron "shielding" effect).
As you can see, ALL of these properties are based on the STRENGTH of the ATTRACTION between the valence electrons and their nucleus.
Download and study the explanations of the trends from today's notes and also look at the tutorial files.

Bio- Reminder: for hw, outline text section 34.1
we reviewed the structures and functions of the skin and then we discussed the immune system process that occurs when skin is cut into the dermis layer. Overall, the skin has many functions and works cooperatively with many other organ systems (circulatory, immune, etc.) in the body.
We reviewed our test on cellular respiration and photosynthesis, noting some of the test skills that would have improved your test scores and made the test easier to answer.
In general, more students could take advantage of the diagrams and pictures from the part I section to help them on the part II section of the test.
We then began to talk about the life process of LOCOMOTION, which involves the musculo-skeletal system of the body.

Chem 7- we continued our discussion of Zeff and OPEL's seeing that ACROSS A PERIOD (left to right) Zeff on the valence electrons increases but the number of OPEL's remains the same; that results in an increasing attraction for valence electrons as you go from the metals to the nonmetals. That is why nonmetals have a higher first ionization energy and a higher electronegativity than metals in a given period. It is also the reason that the nonmetal atoms are smaller than the metal atoms in a given period because the nonmetal electrons are drawn in closer due to the higher Zeff from the nonmetal nucleus.
When considered DOWN A GROUP/FAMILY, the Zeff on the valence electrons remains the SAME but the number of OPEL's INCREASES. Therefore, as you go down a group, the valence electrons are farther and farther away from the nucleus and thus experience less attraction to the nucleus. So, the first ionization energy and the electronegativity decreases down a group but the atomic radius INCREASES down a group.
We will apply Zeff and OPEL's to explain chemistry for the REST OF THE YEAR so it important to draw out and understand how those two factors determine the strength of attraction between the nucleus and the valence electrons.

Chem 8/9- We review Zeff, the effective nuclear charge on an electron; the greater the Zeff on an electron, the stronger it is attracted to the nucleus.
We then looked at the second factor that determines how strongly an atom's nucleus attracts its valence electrons; that factor is the DISTANCE between the nucleus (+) and the electron. The closer the electron is to the nucleus, the stronger the attraction between these oppositely charged particles. How far away, on average, the valence electron is from the nucleus as indicated by the PRINCIPAL ENERGY LEVEL NUMBER of the valence electron, which equals the total number of OCCUPIED PRINCIPAL ENERGY LEVELS (OPEL's).
The higher the P.E.L. number of the electron, the FARTHER away the electron, the LESSER the attraction on that electron from the nucleus.
We saw that, as you go from left to right across a period, Zeff increases (on the valence electrons) and the number of OPEL's STAYS THE SAME causing a greater attraction on the valence electrons of each increasing atomic number element. SO, metals have a weak attraction for their valence electrons and nonmetals have a strong attraction for their valence electrons.
Down a GROUP, the Zeff on the valence electron(s) STAYS THE SAME, but the number of OPEL's increases so the higher atomic number elements in a groups have a LESSER attraction for their valence electrons, which are farther and farther from the nucleus.
We continued our discussion of Zeff and OPEL's seeing that ACROSS A PERIOD (left to right) Zeff on the valence electrons increases but the number of OPEL's remains the same; that results in an increasing attraction for valence electrons as you go from the metals to the nonmetals. That is why nonmetals have a higher first ionization energy and a higher electronegativity than metals in a given period. It is also the reason that the nonmetal atoms are smaller than the metal atoms in a given period because the nonmetal electrons are drawn in closer due to the higher Zeff from the nonmetal nucleus.
When considered DOWN A GROUP/FAMILY, the Zeff on the valence electrons remains the SAME but the number of OPEL's INCREASES. Therefore, as you go down a group, the valence electrons are farther and farther away from the nucleus and thus experience less attraction to the nucleus. So, the first ionization energy and the electronegativity decreases down a group but the atomic radius INCREASES down a group.
We will apply Zeff and OPEL's to explain chemistry for the REST OF THE YEAR so it important to draw out and understand how those two factors determine the strength of attraction between the nucleus and the valence electrons.
We then did an activity in which we looked at various properties of elements and deciphered the location of the elements on a periodic table.

Bio- HW due THURSDAY is to outline text Section 34.1
We began our new unit on the Integumentary (Skin) System, Musculatory (Muscles) System, and the Skeletal (Bones) System.
Often, we will discuss an organism's structures and their functions in terms of evolution i.e. how a structure can be an adaptation, which is a trait that enhances a species' chances of survival in the environment. One student had a question about the rate of human evolution and, how timely, an article was published TODAY on just that question!
Here is the article.
Later in our course, you will be able to understand that article in more detail.
We began by looking at a cross section of the skin showing the different layers and types of cells that make up the ORGAN, the skin. In fact, the skin is the LARGEST organ of the human body.

We emphasized the structure and FUNCTIONS of each layer of cells:
the epidermis has a layer of KERATIN-containing dead cells that protect you from bacteria, chemicals, and heat. The BASAL cells are just underneath the dead cell layer and contain the dark pigment, MELANIN, which absorbs harmful UV rays/photons to protect against cell mutations.
The main layer of skin, the DERMIS, is underneath the epidermis and contains hair follicle cells surrounded by oil/sebaceous glands, various neurons/nerve cells, sweat glands that lead up to pores at the top of the epidermis, muscle fibers, and blood vessels. The dermis functions in regulation/homeostasis by responding to the environment via its nerve cells, muscle fibers, and sweat glands (thermo-regulation/heat regulation via sweating).
There is a layer of fat cells beneath the dermis to provide insulation, protection, and energy.

Chem 7/8- we reviewed characteristics of metals and nonmetals and saw some examples of each.
We then introduced the TWO most important factors in determining the chemical properties of an element via the attraction of the nucleus for its valence electrons.
The first factor is Zeff (EFFECTIVE/NET NUCLEAR CHARGE) on the valence electrons. This is calculated by taking the number of protons in the nucleus (the nuclear charge, Z) and subtracting the number of SHIELDING/BLOCKING/KERNEL/INNER P.E.L. electrons. That number is the NET positive charge that is attracting the valence electron to the nucleus.
The greater the Zeff on a valence electron, the stronger its attraction to the nucleus!
The other factor is how far away, on average, the valence electron is from the nucleus as indicated by the PRINCIPAL ENERGY LEVEL NUMBER of the valence electron, which equals the total number of OCCUPIED PRINCIPAL ENERGY LEVELS (OPEL's).
The higher the P.E.L. number of the electron, theFARTHER away the electron, the LESSER the attraction on that electron from the nucleus.
We saw that, as you go from left to right across a period, Zeff increases (on the valence electrons) and the number of OPEL's STAYS THE SAME causing a greater attraction on the valence electrons of each increasing atomic number element. SO, metals have a weak attraction for their valence electrons and nonmetals have a strong attraction for their valence electrons.
Down a GROUP, the Zeff on the valence electron(s) STAYS THE SAME, but the number of OPEL's increases so the higher atomic number elements in a groups have a LESSER attraction for their valence electrons, which are farther and farther from the nucleus.
We will apply this information to each periodic trend to see how these factors affect each property of elements.

Chem 9- we reviewed characteristics of metals and nonmetals and saw some examples of each.
We then introduced the TWO most important factors in determining the chemical properties of an element via the attraction of the nucleus for its valence electrons.
The first factor is Zeff (EFFECTIVE/NET NUCLEAR CHARGE) on the valence electrons. This is calculated by taking the number of protons in the nucleus (the nuclear charge, Z) and subtracting the number of SHIELDING/BLOCKING/KERNEL/INNER P.E.L. electrons. That number is the NET positive charge that is attracting the valence electron to the nucleus.
The greater the Zeff on a valence electron, the stronger its attraction to the nucleus!
The other factor is how far away, on average, the valence electron is from the nucleus as indicated by the PRINCIPAL ENERGY LEVEL NUMBER of the valence electron, which equals the total number of OCCUPIED PRINCIPAL ENERGY LEVELS (OPEL's).
The higher the P.E.L. number of the electron, theFARTHER away the electron, the LESSER the attraction on that electron from the nucleus.
Tomorrow, we will work out some examples and apply this information.

Bio- we had our Photosynthesis/Cellular Respiration test today.
We then organized our lab folders and watched a segment from "60 Minutes" on a potential treatment for drug addiction. The clip showed compelling "anecdotal evidence" (basically just word-of-mouth stories that may or may not be true and that do not involve a control group or scientific investigation) that the medication, "Pro-Meta", significantly reduces an addictive cravings. What we did NOT get to see was the SCIENTIFIC proof involving "double-blind", controlled studies. Check out the rest of the video and see whether the claims for Pro-Meta have a substantial scientific basis.
http://www.cbsnews.com/stories/2007/12/07/60minutes/main3590535.shtml
If they do not, how do you account for all of the success stories?

Chem 7- we looked at the typical characteristics of metals: luster, malleability, ductility, good electrical and thermal conductivity, easily lose their valence electrons to form smaller positive cations, solids (except for Hg).
We discussed their physical and chemical opposites, the non-metals: dull, brittle, poor thermal and electrical conductivity, easily gain electrons to become larger negative anions.
We noted that the SEVEN SEMIMETALS (metalloids) have properties that are between those of metals and non-metals and that they are important "semi-conductors" that are used in electronic equipment.
We will look at and EXPLAIN the Periodic Law, tomorrow.

Chem 8/9- we looked at the typical characteristics of metals: luster, malleability, ductility, good electrical and thermal conductivity, easily lose their valence electrons to form smaller positive cations, solids (except for Hg).
We discussed their physical and chemical opposites, the non-metals: dull, brittle, poor thermal and electrical conductivity, easily gain electrons to become larger negative anions.
We noted that the SEVEN SEMIMETALS have properties that are between those of metals and non-metals and that they are important "semi-conductors" that are used in electronic equipment.
We used the Reference Tables to see the typical trends in ionization energy, electronegativity, or atomic radius/size across a period or down a group. It's good just to keep it simple and use Li through F for the "across a period" trend and to use Li to K for the "down a group" trend.
We then finished our Periodic Table coloring activity and did some of the questions on another worksheet.
We will look at and EXPLAIN the Periodic Law, tomorrow.

Bio- Tonight, I'm posting an additional comprehensive written practice test with a separate ANSWER KEY. Do this test for great practice for Monday's exam!
I also posted the answers to the objectives that we went over today in class.
Also this weekend, make sure that you practice drawing out our "big picture" that tied together photosynthesis and respiration.
Email me if you have specific questions from your study after you have done the above practice test and checked the answer key.
Good luck on Monday!

Chem 7/8- Atomic Structure Test Corrections are due on Monday. You do not have to explain why you chose YOUR wrong answer. You DO have to explain, in detail, typically with a labeled drawing or diagram, the correct answer to the question.
Today, we learned the names of some of the Groups/Families of elements (down a column) and noted the similar characteristics of the elements in a given group.
Check out the video on Blackboard that shows the various Alkali metals reacting with water.
We also saw the difference between a relatively stable/inert element, He, and a relatively reactive (though NOT unstable) element, H.
We then did a lab activity highlighting the various different types of elements/groups that make up the Periodic Table.

Chem 9- Atomic Structure Test Corrections are due on Tuesday. You do not have to explain why you chose YOUR wrong answer. You DO have to explain, in detail, typically with a labeled drawing or diagram, the correct answer to the question.
Today, we learned the names of some of the Groups/Families of elements (down a column) and noted the similar characteristics of the elements in a given group.
Check out the video on Blackboard that shows the various Alkali metals reacting with water.
We also saw the difference between a relatively stable/inert element, He, and a relatively reactive (though NOT unstable) element, H.
We then did a lab activity highlighting the various different types of elements/groups that make up the Periodic Table.

Bio- I will post the test objective questions for Monday's exam on Blackboard tonight.
Today, we finished our big picture of photosynthesis and cellular respiration by focusing on the part of aerobic respiration that occurs in the mitochondria: the Krebs cycle, which takes the
acetyl co-A (2C) made from the pyruvic acid (3C) that was transported into the MITOCHONDRIA via active transport. The Krebs Cycle further breaks down the acetyl co-A to CO2 and forms more H-carrying molecules, like NADH, which ultimately donate the H to Oxygen in the last part of aerobic respiration, the ELECTRON TRANSPORT CHAIN (ETC). So during the ETC, H2O is formed from the oxygen and H (from NADH) and a LOT of ATP is formed in the process.
Overall, aerobic respiration yields a NET of 36 ATP formed per one glucose molecule respired.

If you practice drawing out (many times) our "big picture" including all or the organelles and chemical reactions therein, you will have a GREAT and comprehensive reference that you can draw out during the exam and from which you will locate most of the answers.

Make sure that you see that the products of respiration are the reactants of photosynthesis and vice-versa. Also, photosynthesis is a (sunlight) energy-REQUIRING process whereas respiration is an energy-RELEASING/PRODUCING process (36 ATP aerobically, 2 ATP via anaerobic respiration/fermentation.
Speaking of fermentation, here are two video links, one to alcoholic fermentation
http://www.youtube.com/watch?v=JbKQfzutmf4&feature=related
and one showing both lactic acid fermentation and alcoholic fermentation:
http://trc.ucdavis.edu/biosci10v/bis10v/media/ch06/fermentation.html
We then explained our cellular respiration rate lab in detail, going over what happened during each step and getting the purpose of each step.
We identified the independent variable (the amount of exercise), the dependent variable (the acidity of the aqueous solution from the carbon dioxide that was breathed out), and the control group (the flask with just tap water and carbon dioxide from the air).
We showed that, the greater the energy needed for exercise, the greater the rate of respiration needed to supply the ATP for any muscle contractions, increased heart rate, etc, and therefore, the greater quantity of products of respiration, CO2 and water vapor, breathed out.
Tomorrow, we will review for Monday's important exam.

Chem 7- we started our new unit: the Periodic Table and Periodic Trends (Periodicity).
We noted the various names and meanings of the chemical symbols of the elements. We noted the IUPAC naming system for as yet unnamed elements- the system uses a prefix for each digit in the atomic number, e.g. element 113 is "ununtrium or ununtri-ium" and element 115 is "ununpentium". We then discussed the PERIODIC LAW, which are the repeated typical trends in various properties (atomic size, ionization energy, etc.) that occur as elements are considered across a Period or down a Group/Family. The PERIODIC LAW emerges ONLY when the following two criteria are used to assemble the periodic table:
1. The elements are arranged in order of atomic number/# of protons
2. A new Period (row) begins each time an electron is placed into the next highest PRINCIPAL ENERGY LEVEL.

With this arrangement, elements within a given group/family (column) tend to have similar CHEMICAL properties, which is very useful in predicting chemical reactions.
We also notice, for example, that atomic size/radius decreases across each period (from left to right) and atomic size increases down a group.
The net attraction between the nucleus and the various electrons of an atom will determine its various properties. This will allow us to EXPLAIN all of the various periodic trends of the PERIODIC LAW.
Check out this guy's site. This chem-nut CARVED a wooden periodic table and his site has great info/videos on each element.

Chem 8/9- we started our new unit: the Periodic Table and Periodic Trends (Periodicity).
We noted the various names and meanings of the chemical symbols of the elements. We noted the IUPAC naming system for as yet unnamed elements- the system uses a prefix for each digit in the atomic number, e.g. element 113 is "ununtrium or ununtri-ium" and element 115 is "ununpentium". We then discussed the PERIODIC LAW, which are the repeated typical trends in various properties (atomic size, ionization energy, etc.) that occur as elements are considered across a Period or down a Group/Family. The PERIODIC LAW emerges ONLY when the following two criteria are used to assemble the periodic table:
1. The elements are arranged in order of atomic number/# of protons
2. A new Period (row) begins each time an electron is placed into the next highest PRINCIPAL ENERGY LEVEL.

With this arrangement, elements within a given group/family (column) tend to have similar CHEMICAL properties, which is very useful in predicting chemical reactions.
We also notice, for example, that atomic size/radius decreases across each period (from left to right) and atomic size increases down a group.
The net attraction between the nucleus and the various electrons of an atom will determine its various properties. This will allow us to EXPLAIN all of the various periodic trends of the PERIODIC LAW.
We then took a tour of the Periodic Table and noted that most of the elements are METALS. Metals are the elements to the LEFT of the "stairway" on the Periodic Table.
Group I metals are called alkalI metals (mnemonic = I is Roman numeral "one") and Group II metals are called alkaline earth (mnemonic = group II, TWO words, alkaline earth). Both of these groups of metals form alkaline (basic) aqueous solutions when those metals react with water.
Group 17 is the HALOGENS ("salt formers"). At room temperature and standard pressure, Fluorine and Chlorine are gases, Bromine is a liquid, and Iodine is a solid.
Group 18 is the Noble or Inert Gases, which have the most stable valence electron configurations- a complete "octet" of eight valence electrons, filled s AND p sublevels (except for He which has just a filled 1s sublevel).
We finished our emission spectrum/flame test write-up and then did a Periodic Table lab activity, identifying the various groups and activities of elements.
Check out this guy's site. This chem-nut CARVED a wooden periodic table and his site has great info/videos on each element.

Bio- hw text section 9.3 outline is due on Thursday. Bring in your Aerobic Respiration Rate lab to be completed in class tomorrow.
We looked at the big picture of photosynthesis and cellular respiration starting with the macroscopic view of a plant leaf and then focusing on the processes that go on in an individual plant leaf cell. We got through the photosynthesis part of the big picture and up to the glycolysis part of cellular respiration. Tomorrow, we will complete the whole picture and see the inter-relationship between the two processes. After looking at the leaf parts and the individual plant cells, we detailed the processes INSIDE each cell in the relevant organelles (the chloroplasts, mitochondra) and in the cytoplasm within a cell. We looked at even smaller details as we discussed the processes in different parts of each organelle, the granum and the stroma of the chloroplast as well as the inner mitochondrial membrane of the mitochondria.
We ultimately focused on the smallest possible units involved in photosynthesis and respiration: the molecules- chlorophyll, water, carbon dioxide, enzymes, ATP, glucose, oxygen, pyruvic acid, etc. and noted their respective locations within the organelles or cytoplasm of a cell.

Chem 7/8- took the Atomic Structure unit exam; so far I am impressed with the explicit detail provided in your answers, the attention to test skills, and the correct spelling of the word "neutron"- very good!
We completed the discussion and write-up of the Emission Spectra and Flame Test lab.

Chem 9- took the Atomic Structure unit exam; I'll try to have them graded by tomorrow.
Tomorrow, we begin the Periodic Table, which is a natural continuation of the Atomic Structure unit. So, if there was anything that gave you trouble on the test today, make sure that you get that cleared up (written review, extra help, repetition, practice) before we get into this new unit.

Bio- we focused on the other anaerobic respiration/alcoholic fermentation. This process occurs in yeast and certain bacteria. As in lactic acid fermentation, glucose is first broken down via glycolysis into 2 pyruvic acid molecules causing a net production of 2ATP and 2 NADH molecules. However, in alcohol fermentation, ETHANOL, a 2-carbon molecule is formed. Therefore, the pyruvic acid molecules have to be further broken to a 2-carbon molecule (acetaldehyde) and carbon dioxide. REMEMBER, whenever alcohol is produced via fermentation, so is carbon dioxide; you can remember this by picturing BEER or CHAMPAGNE (the bubbles are carbon dioxide!) both of which are made via alcoholic fermentation by yeast or bacteria!
Recall that NO carbon dioxide is made in lactic acid fermentation because lactic acid is a 3-carbon molecule that is not broken down further.

We then discussed cellular respiration that uses oxygen: aerobic respiration. This process, by completely breaking down glucose to carbon dioxide and water, transfers much more energy from the bonds of glucose to the bonds of ATP molecules; in fact, instead of just 2 ATP, a total of 36 ATP molecules are formed per molecule of glucose aerobically respired. Aerobic respiration involves sending the pyruvic acid molecules (formed via the glycolysis of glucose in the cytoplasm) to the MITOCHONDRIA where they will be broken down in the Krebs/Citric Acid Cycle and then, using oxygen, more ATP will be produced via the ELECTRON TRANSPORT CHAIN of proteins that line the inner mitochondrial membrane.

We then did a lab that showed the increased rate of cellular respiration that must occur when your cells need more energy due to increased exercise. This increased respiration rate shows up as an increase in the production of carbon dioxide, which is one of the main products of respiration.
We measured the amount of carbon dioxide breathed into a solution of water and acid-base indicator by neutralizing the carbonic acid (formed when CO2 reacts with water) with a base. We saw that the carbonic acid was neutralized when the acid-base indicator turned pink as the solution became basic.

Chem 7- we discussed "nuclear physics" today; we focused on the four types of emanations that come from unstable isotopes called radioisotopes. The radioisotopes and possible emitted particles are listed on Tables N and O on the Reference Tables. The positive particles that can be emitted from unstable nuclei are alpha particles ( +2 charge and ~ 4 amu mass) or positrons
(+1 charge and very small mass ~ 1/1836 amu). The negative particles that emanate from some unstable nuclei are electrons/beta (-) particles. Some unstable nuclides emit high energy GAMMA photons.
We then drew out the Bohr and QM electron configurations of various cations and anions. ONLY METALS lose electrons to form cations. Metals lose their valence electrons and become POSITIVE cations with a noble gas electron configuration. ONLY NONMETALS gain electrons to form negative anions with a noble gas configuration and an OCTET (eight) of valence electrons (except for H).
Good luck on Wednesday's exam!

Chem 8/9- we discussed "nuclear physics" today; we focused on the four types of emanations that come from unstable isotopes called radioisotopes. The radioisotopes and possible emitted particles are listed on Tables N and O on the Reference Tables. The positive particles that can be emitted from unstable nuclei are alpha particles ( +2 charge and ~ 4 amu mass) or positrons
(+1 charge and very small mass ~ 1/1836 amu). The negative particles that emanate from some unstable nuclei are electrons/beta (-) particles. Some unstable nuclides emit high energy GAMMA photons.
We then drew out the Bohr and QM electron configurations of various cations and anions. ONLY METALS lose electrons to form cations. Metals lose their valence electrons and become POSITIVE cations with a noble gas electron configuration. ONLY NONMETALS gain electrons to form negative anions with a noble gas configuration and an OCTET (eight) of valence electrons (except for H).
We then discussed our flame test and emission spectra exam. In order to detect the elements in an unknown mixture's spectrum, ALWAYS look at the KNOWN spectra first and check that EACH AND EVERY emission line from the KNOWN is also in the UNKNOWN. If that is not the case, then the KNOWN element is NOT in the UNKNOWN mixture of elements.
We reviewed electron transitions, excited state electrons, and ground state electrons. Remember, PHOTONS (specific-energy packets) can ONLY be formed when an electron LOSES energy as it undergoes a TRANSITION from a higher energy level to a lower energy level. That energy lost is TRANSFORMED into a PHOTON of energy!
Good luck on Wednesday's exam!

Bio -we finished our section on Photosynthesis and Plant Leaf Anatomy and Function; we noted that guard cells form and sometimes close the stomates on the lower epidermis of a leaf in order to regulate TRANSPIRATION, the loss of water from the leaf. Water mainly enters most plants through their ROOTS and the water molecules, via cohesion to each other and adhesion to the xylem tissue, are pulled up the stem and to the leaves; this process is called TRANSPIRATIONAL PULL.
We took a mini-quiz to check our test skills and to make some inferences from the information that we have seen so far.
We then revisited the energy RELEASING process of cellular respiration in which the chemical potential energy that is stored in the bonds of glucose is extracted and transferred to molecules of ATP, which are ultimately used for their stored chemical energy whenever an energy-requiring life process occurs in an organism.
We noted the two main types of cellular respiration, AEROBIC (uses oxygen) RESPIRATION and ANAEROBIC (no oxygen used) RESPIRATION.
A LOT more ATP can be made via the aerobic pathway (36 ATP per molecule of glucose broken down) compared to the amount of ATP that can be made via anaerobic respiration/FERMENTATION (only 2 ATP per glucose molecule broken down).
We discussed the two types of fermentation: lactic acid fermentation and alcoholic (ethanol) fermentation.
Depending on an organism's genes that code for particular fermentation enzymes, a given organism may ferment glucose to pyruvic acid to alcohol/ethanol and CO2
OR
an organism may ferment glucose to pyruvic acid to lactic acid. Humans carry out anaerobic lactic acid fermentation in the cytoplasm of their cells whenever their is insufficient oxygen to meet the energy demands of the cells i.e. during strenuous exercise. This lactic acid production produces the "feel the burn" sensation in muscle cells.

Chem 7/8- we practiced the various ways of keeping track of the energy and relative locations of electrons in an atom. We did the Bohr electron configurations, the QM electron configuration (with s,p,d,and f sublevels of electron energy), Orbital Diagrams, and the all-important Lewis Dot Structures.
We noted the mathematical relationship between principal energy level number, n, and the number of sublevels in a given PEL, the total number of orbitals in the PEL, and the maximum number of electrons that could occupy a given PEL.
We also noted the "blocks" of elements on the Periodic Table along which particular sublevels are filled with electrons e.g. Groups 1 and 2 are the "s" block and Groups 13 - 18 are the "p" block. Knowing these blocks makes it easier to write the correct QM electron configuration for an element.
Tomorrow, we will practice for our exam and talk a bit about nuclear emanations that come from radioactive isotopes.

Chem 9- we practiced the various ways of keeping track of the energy and relative locations of electrons in an atom. We did the Bohr electron configurations, the QM electron configuration (with s,p,d,and f sublevels of electron energy), Orbital Diagrams, and the all-important Lewis Dot Structures.
We noted the mathematical relationship between principal energy level number, n, and the number of sublevels in a given PEL, the total number of orbitals in the PEL, and the maximum number of electrons that could occupy a given PEL.
We also noted the "blocks" of elements on the Periodic Table along which particular sublevels are filled with electrons e.g. Groups 1 and 2 are the "s" block and Groups 13 - 18 are the "p" block. Knowing these blocks makes it easier to write the correct QM electron configuration for an element.
Tomorrow, we will practice for our exam, write up our flame test and emission spectra lab, and talk a bit about nuclear emanations that come from radioactive isotopes.

I'm currently scanning the answers to the worksheets that we did in class for the past two weeks. The files will be on Blackboard within the hour...
Check your work and be ready with questions for our test review session tomorrow.
Thanks.

I just posted two more worksheets, one on Models of the Atom and the other on Electron Configurations and Orbital Diagrams. Both worksheets have their respective answer keys at the end of the file so that you can get instant feedback on your answers. If you need further clarification on a question, check your text, notes, etc. and then ask me about the question at extra help or at the beginning or end of class.
See you on Monday.