Chemblog!

AP: The Periodicity practice test worksheets on the website. Practice with them for the next test. The brief explanations on the answer sheet may not be adequate so just use the typical AP-level explanations for any of those questions ( you know, Zeff, OPELs, e-e- repulsion ).

Honors: continue to study for Friday's multiple choice test.

We will have the next Honors Chem Exam this Friday. This will be a multiple-choice format exam worth 100 points. The exam will cover the periodic table unit in its entirety, which also requires knowledge of atomic structure (electron configurations).

Check your notes, powerpoints, review book hw and unit worksheets that were posted earlier.

Since this is all review material, you should know exactly what to do relatively quickly. The first half should take you all of a half-hour. The second half is mostly stoichiometry so the calculations will take you somewhat longer to do. If you have any trouble with this assignment, you must thoroughly review that material in the text/notes or email me for guidance. In order to get a 5 on the AP exam, the answers to the questions in this assignment must come relatively quickly and easily.
See you on Monday. Have a restful, enjoyable vacation.
p.s. I had to add one more question ( #40 ) to the assignment to make sure that we're all bulletproof on bond dissociation energy questions.

A nice turnout at extra help for AP; unprecedented (this year). That bodes well for tomorrow I hope.
For reassurance, you will not be asked about things that we didn't cover in the notes. Specifically, there was a question in extra help about electronic configuration of transition metal ions. Though I definitely mentioned Fe 2+ and Fe 3+ in class, we have not formally gone over those (and the EXTREMELY important "first in , first out" rule) so I won't put questions about electronic configurations of transition metal ions BUT all other configurations and explanations thereof will be on the test. The AP exam (and I) will NOT expect you to know anomalies! They/I will TELL you what the anomaly is and you will have to account for/explain the anomaly based on your knowledge of the quantum mechanical atom and energy interactions among electrons and protons.
Since the last exam, we finished the quantum (wave) mechanical model of the atom and then we started chemical periodicity so, in addition to earlier quantum (repeat) material (recall your main mistakes from the last exam), the test will be on said recent material.
Tomorrow. One day. One test. Then....vacation! ...and vacation assignment (sigh)...which will be review material so you "should" be able to finish it quickly based on how much knowledge you have retained.

the first test of the second quarter...let's start strong...written-response format...next Monday AND Tuesday (total of two periods to complete the exam). Test will cover material (all notes and homework) from the Wave-Mechanical (Quantum) Model of the Atom through the Periodic Trends covered this week...test will likely be worth 150 total points...practice your written explanations and drawings...
update: the test covers material up to and including the explanations of periodic trends (across any period from left to right and also down any group); we covered six trends or explanations ending with the periodic trend in electronegativity. The worksheets that I uploaded on Friday will provide additional practice for this test (you can ignore the questions on "dot structures" and types of compounds formed).
Remember, you will need to APPLY/EXPLAIN the EFFECT of the effective nuclear charge and also the EFFECT of the number of OCCUPIED principal energy levels ON whatever is asked in the question. If you merely state that a given trend is due to, say, high Zeff and a low number of principal energy levels, you will receive little to no credit.
TIP: Start off by writing a key in the upper left corner of your first page:
Zeff = effective nuclear charge
OPELs = occupied principal energy levels
You may not abbreviate ordinary words; your test is not a chatroom. Do not say that "NRG" is energy (unbelievable that some did that on the last exam).
Also, carefully read and practice the words in our spelling list ; we're in the second quarter so spelling and grammar should be excellent by now. Again, I suggest that you avoid pronouns in your written explanations unless you are absolutely sure that you are using the pronouns properly and unambiguously.
The exam will be given on Monday but a few questions will not be seen until Tuesday; I will return Monday's work to you to start the exam on Tuesday so don't worry about finishing all of your answers on Monday. Just put each answer on a separate page if you want to skip around.
Looking forward to a strong WRITTEN start to this quarter.
Good luck on Monday and Tuesday!
Mr.Cicale

Here is a hint related to what I spoke about in class; this question isn't as difficult as it seems.
Recall our simple stoichiometry calculations of empirical formulas from the percent composition of each element in a compound.
For example, water is 88.9 % oxygen by mass and 11.1% hydrogen by mass. IF WE KNEW the molar mass of water (from gas density measurements, recall that dRT/P = molar mass, assuming ideal gas behavior), which we DO know is 18.02 grams, then we can get the atomic masses of oxygen and hydrogen by multiplying the % mass of the element by the molar mass of the compound.
For example:

relative atomic mass of O = 88.90% x (18.02 amu per molecule) = 16.0 amu
relative atomic mass of H = 11.10% x (18.02 amu per molecule) = 2.00 amu

NOTICE that the atomic mass of H is incorrect! That is because water contains TWO H atoms per molecule.
Thus, the Cannizaro method is used for comparing the relative atomic mass of H in various compounds and THEN finding the SMALLEST DIFFERENCE in relative mass of H among the compounds. That difference most likely equals the atomic mass of H.

example:
in HCl,

H is 2.764% by mass and Cl is 97.236% by mass

multiply by the given molar mass ( from gas density measurements, recall that dRT/P = molar mass )of the compound:
relative atomic mass of Cl: 97.236% x 36.4609 amu per molecule = 35.453 amu
relative atomic mass of H: 2.764% x 36.4609 amu per molecule = 1.0078 amu

so the smallest difference in relative atomic mass (2.00 amu - 1.0078 amu) should be the actual atomic mass of H = .9922 amu which is pretty close to 1.0079 amu.

Naturally, to do gas density calculations for Zinc chloride, one would have to vaporize the salt AND assume ideal gas behavior...not a pretty combination. However, a mass spectrometer can be used to obtain the molar mass of any simple compound.

Honors:
Here is a link to a site that has videos on periodic trends:
http://cwx.prenhall.com/bookbind/pubbooks/petrucci8/chapter10/deluxe.html

AP: same site but this is the chapter on electron configurations and quantum numbers of the Schroedinger equation.
http://cwx.prenhall.com/bookbind/pubbooks/petrucci8/chapter9/deluxe.html

click on the "Student Tutorials" link and enjoy the video explanations/descriptions.

Cheers to those who put in the time to take the exam today. Sorry that we got the runaround in the auditorium- that was unprecedented- but we finally found that there is no place like home (229) or next door (225).
Early results are in: full class average on this 100 question exam: 92.
That means that most of you boosted your average as well as reinforced most of the important information that we have covered this quarter.
Thanks for going the distance.
Mr.Cicale

ENTER THE ORBITRON!
Here is the link showing the 3-dimensional orbitals OF any given energy SUBlevel:
http://www.shef.ac.uk/chemistry/orbitron/

Make sure that you can state the four quantum numbers associated with a given electron in any given orbital.

I'm copying this post from another teacher's blog: http://www.kimberlyswygert.com/

You should show this post to your parents especially if you previously went to public school (where the following methods are strictly applied and enforced). This post hits the nail on the head regarding the institutionalized failure in education that has plagued young students for the past 10 to 15 years; you are lucky if you have parents or tutors who can help you to compensate for this malpractice:

The parents' fight against fuzziness

The NYTimes opens an article about the new "innovative" math with a provocative anecdote:

LAST spring, when he was only a sophomore, Jim Munch received a plaque honoring him as top scorer on the high school math team here. He went on to earn the highest mark possible, a 5, on an Advanced Placement exam in calculus. His ambition is to become a theoretical mathematician.

Jim might have seemed the veritable symbol for the new math curriculum installed over the last seven years in this ambitious, educated suburb of Rochester. Since seventh grade, he had been taking the "constructivist" or "inquiry" program, so named because it emphasizes pupils' constructing their own knowledge through a process of reasoning.

Jim, however, placed the credit elsewhere. His parents, an engineer and an educator, covertly tutored him in traditional math. Several teachers, in the privacy of their own classrooms, contravened the official curriculum to teach the problem-solving formulas that constructivist math denigrates as mindless memorization.

The article does a nice job of capturing the frustration parents feel with math instruction so "progressive" and devoid of "mindless memorization" that their sixth-graders are unable to make change from a $20 bill. What's more, the parents who are helping their children memorize multiplication tables are derided as "helicopter parents":

Susan Gray, the superintendent, attributed the criticism of the math program to "helicopter parents" who are accustomed to being deeply involved in all aspects of their children's lives. "Because the pedagogy has changed, the parents who knew the old ways didn't know how to help their children," she said. "They didn't have the knowledge and skills to support their children at home. There's a security in memorization of math facts, and that security is gone now."

Um, is that supposed to be an advantage of constructivist math? That engineers, scientists, and doctors who used to be able to expect their kids to make change can no longer do so? And I'd like to point out to Ms. Gray that the term "helicopter parents" was developed to mock those overprotective souls who keep a close eye on kids who've left the nest and moved on to college. Applying the term to parents who are horrified at how handicapped their young kids are by lack of "drill and kill" math knowledge is condescending and nasty.

The article's primary shortcoming is its lack of links to bloggers, educators, and teachers who have been fighting this battle for quite some time. At the very least, the author should have linked to Bas Braams and Mike McKeown for their tireless work in this area. To get the best sense of the ongoing battle to return common sense and multiplication tables back to public school math, you can also click on over to the NYHOLD site and just keep scrolling. A recent paper by Stanley Ocken, a professor of mathematics at CUNY-NY, sums things up nicely:

...the New York State 4th and 8th grade assessments are weak in computational and pre-algebra skills. Those exams include lots of word problems dealing with everyday situations, but the actual math skills required are minimal [What's more, such items place a heavy reading load on students, and often end up measuring more reading comprehension than math skills]. That’s a direct result of the vision described in the NCTM Standards: computation with standard algorithms must be removed from its dominant place in the elementary curriculum. After all, you can get the answer with a calculator.

The problem with that recommendation is its effect on students’ future ability to handle algebraic symbolism efficiently, fluently, accurately. It’s necessary, but not sufficient, that kids learn the multiplication table cold. Once that's done, they need to assemble basic operations into more complex tasks. That’s why they still need to practice standard algorithms for multi-digit multiplication and division. It is the experience of sustained number manipulation, with fluency and accuracy as the goal, that establishes a foundation for future success with lengthy algebraic symbol manipulation tasks that are critical in mathematics and science, beginning with a good Algebra II course. And it is the importance of sustained number manipulation that is categorically rejected by the NCTM Standards and by elementary math programs, including Everyday Math, that share the NCTM vision.

This fuzzy math has been lauded by the National Council of Teachers of Mathematics for years as more inclusive and beneficial to students in a high-tech age, and a cursory read of their mathematics standards would seem to support their claims. However, the careful reader will note that, despite their claims that there's no one "right" way to teach math, the NCTM pushes collaborative learning over solitary work, and they present "conceptual understanding" as something that contrasts to, rather than results from, the learning of basic skills. Calculators are also a integral (ha) part of their brave new vision.

For more criticism of the NCTM and their plan for teaching "conceptual understanding" without having to memorize any formulas, you can click back to old links of mine here, here, here, and here.

And to end with my own anecdotal evidence of sorts, let's just say that everyone I know who tutors high school math, either on the side or as a full-time job, is not having to hunt for pupils, even in the best school districts where the public schools are considered to be very good. The tutors I've spoken with don't describe their pupils as being pushed by "helicopter parents," either, but say that the outside is tutoring is a necessity to balance the undemanding school curricula.

Just tallied all of the grades for the quarter (not including Monday's late bonus exam).
On the lab exam, practically a dead heat (that's a tie in horse racing argot):
D: 91.2
E: 90.5
B: 90.2
I'm satisfied with the results although I do have two qualifications: almost exclusively, the classes lost points on questions that had the right numerical answer with the WRONG unit among the choices. AFTER and ONLY AFTER you have already written a predicted answer, please read ALL choices . That is a major test-taking skill taught by EVERY reputable test prep company. Also, some of you do not know how to use a calculator especially when a denominator has a large or small number written in scientific notation. I will be happy to show you how to use your calculator. Just see me at extra help.
Thanks for the good results.
Enjoy Sunday!
Mr.Cicale

Question #6 on Part II of the AP exam tests your ability to describe particular
experimental procedures. Since the AP exam has no lab practical component (and NEVER will have one due to the impossibility of standardizing lab equipment among high schools and colleges- can you IMAGINE the "sophisticated" lab equipment used in West Virginia's High Schools? "... okay, class, take your lab balance that you made out of ice cream sticks and manure and weigh the sodium chloride y'all...". As my colleague (who teaches at a private, ritzy academy in Georgia) says, one need not actually PERFORM any labs in this course in order to achieve a 5. He regularly has a 4.7 AP class average among his two classes of 20 SOPHOMORES so I am inclined to believe him. Nevertheless, we will perform some key labs (that typically show up on Q6) this year before the AP exam.

Download the empirical formula determination lab from the website and CAREFULLY read (I daresay memorize) the lab procedure. Part "a" of question 6 will list a bunch of lab equipment and you have to describe how and what you would use to determine the empirical formula of a compound. Part "b" will be a typical and relatively simple calculation or deduction from data. Part "c" is the crucial "critical thinking"- what if something went wrong- question. We will have copious practice with this question type starting with this lab writeup. The key to answering this question type is to FABRICATE numbers that are consistent with the question. Then, your calculation will answer the question for you.
This writeup will count towards your second quarter grade.

Naturally, if you have trouble with this, just see me after class or email me.

Initial scantron results are in and I will have final accurate results after I peruse your tests:
B,D, and E are approximately tied on this test.
Average per class: 90.
Good work- on this exam, compared to last year's classes, this year's classes achieved a significantly higher average.
Paying attention to units and sig figs pays off.
Thanks,
Mr.Cicale

pretty koolio links to interactive periodic tables with visualizations and info about your favorite elements:
Honors and AP, check them out:

http://www.colorado.edu/physics/2000/applets/a2.html

This one has everything you always wanted to know but were afraid to ask:

http://www.webelements.com/

nice pics...
http://www.lenntech.com/periodic-chart.htm

Last day advice for tomorrow's tests...
Honors: multiple choice format...make sure that you know how to add, subtract, multiply and divide measurements (numbers WITH units!) to the correct number of significant figures...I noticed several errors on many labs regarding this. Just know and follow the rules for this skill or you will get those (many) questions wrong.
bottom line: know the lab test objectives that were posted a few days ago. Use the test-taking skills that I recommended for the last exam (keywords circled/underlined, all work written/drawn out and THEN look for a matching answer).

AP: Combined Thermo and Quantum Exam...
Know the BIG difference between enthalpy of FORMATION of a compound and the enthalpy of ANYTHING ELSE. These two quantities refer to COMPLETELY different chemical reactions. This difference was demonstrated in countless examples among the hw, practice tests and notes. Take heed of EACH term/definition. You CANNOT use different terms interchangeably in science, especially in Thermo.
Know how to do calorimetry problems and, if specific heat of water or a solution AND the heat capacity of the calorimeter are listed SEPARATELY, then you must use BOTH terms simultaneously in your energy EQUATION.
Also, change in internal energy is NOT equal to the change in enthalpy under most conditions (especially if any work is done by or on the system).
The Quantum stuff will cover mostly the Bohr Model and evidence/conclusions/explanations leading to the development of said model. Also, the quantum energy calculations i.e. bond dissociation energies based on photon energy data, Bohr energy level calculations...

I hope that you end the first quarter on a high note!
Monday afternoon: optional bonus comprehensive quarterly multiple choice exam for Honors. Location to be announce on Monday (probably will be in the auditorium).

The objectives for Thursday's multiple choice lab test are on the class website; I'm at extra help every day after school if you need help in finding the answers or if you need to see some examples of calculations. Last year's classes did not do well so make sure that you know those objectives.
Thanks.

Here is a helpful site of quantum atom unit animations, etc.

http://cwx.prenhall.com/bookbind/pubbooks/petrucci8/chapter9/deluxe.html

Click on " Student Tutorials" to see the list of animations.

This site is the bomb also:
http://highered.mcgraw-hill.com/sites/0073656011/student_view0/chapter7/elearning_session.html

Just scanned the 'trons and here is the early analysis:
D Period: Class AVERAGE = 96 yessssssss.
B Period: 94 woot! quite a few hundreds!
E Period: 91 not bad.

...will be given this Friday. Expect approximately 33 multiple choice questions. Use the same test-taking skills: underlining keywords, answer exactly what the question asks for; you won't be graded on the work shown but you should show your work anyway to prevent yourself from making errors; don't do a problem only in your mind, write it down instead.
Typically this test is a nice grade booster for those who study by doing lots of practice questions and who also show their work and do not misread the questions.

Commentary: Kudos and plaudits to our school for recognizing the fun and funny Halloween tradition. If you read/listen to/watch the news (which should be a daily, though depressing, part of your routine), you know that some schools have cancelled Halloween parties because someone was offended by kids in costumes asking for candy. Dire prediction: Within 20 years, there will be no Halloween festivities at any public schools. Halloween will be replaced by a celebration of "Autumn". How nice. Of course, I'll still be coming in dressed as Ali G saying " Does you fink vat 'alloween is bollocks?"

Look how bent out of shape some people are over this innocuous custom that keeps Nestle, Hershey, and Mars in business:
Yesterday, President Hugo Chavez cautioned Venezuelan parents to protect their children from Halloween with a spooky warning that the US tradition is rooted in "terrorism."

"What they have implanted here, which is really a 'gringo' custom, is terrorism," Chavez said, quoted in the local press. "They disguise children as witches and wizards, that is contrary to our culture."

Anyway, at the very least, the costume contest demonstrated our students' artistic creativity/imagination, provided some comic relief and kept a quaint little custom alive.
I can't wait to protest at a local school board meeting in 2021 about how OFFENDED I am by the idea of celebrating the base and vulgar season of Autumn..."can't you feel the cold chill and darkness that besets and plagues us every Autumn!" (led away in shackles to Bellevue)
I'm actually a fan of the Fall, though.
Now, back to studying (writing).