Monday, December 18, 2006
Monday before Break
AP: I hope that you found today's exam palatable. Most years, the results are more than decent on this exam; not that the exam is easy but this exam tests skills that can be perfected after a few days of practice.
Tomorrow, I will suspend our current unit (intermolecular attractions) and do some of the more difficult problems from Chapters 11 and 12, which are assigned over the break.
I will be putting up a RIDICULOUS number of problems with worked out solutions to help guide you through the two units and, of course, I am an email away, if you need assistance.
Honors: thanks to a couple of students who pointed out a couple of errors on the polyatomic ion worksheet and one error on the salt-naming worksheet. I will correct those errors and post them tonight (on the class webpage, look for the words "updated file" next to the file name.
Today, we went over some of the test-taking errors from the last test. Own your mistakes, (in LIFE, there is seldom better advice than this!), correct them, and learn from them so that you can improve and grow academically.
Then, we reviewed the stock system, which MUST be used for salts of transition metals (very few exceptions: Ag, Cd, Zn salts).
We also learned how to name hydrated salts (HYDRATES) in which there is a certain integer ratio of water molecules embedded in the ionic lattice per formula unit of the salt.
IN D PERIOD but NOT G PERIOD, we finished with the PREFIX system for naming molecules. NO SALTS (except hydrates) HAVE PREFIXES SO, IF YOU EVER SEE A PREFIX IN A FORMULA, YOU MUST BE LOOKING AT THE NAME OF A MOLECULE i.e. carbon dioxide..."di" indicates "must be a molecule". NOTE: unlike salts, there is NO "geometric lattice" of atoms in a molecule; each individual molecule is a separate, unique, individual entity. For example, every separate, individual carbon dioxide molecule has EXACTLY ONE carbon ATOM (double) bonded to TWO oxygen ATOMS, one oxygen atom on either side of the carbon atom. The Lewis structures of molecules show an actual individual molecule but the Lewis structures of salts cannot and do not depict the entire lattice of ions. Lewis structures of salts ONLY show one FORMULA UNIT of the ionic lattice, so Lewis structures of salts cannot possibly depict the true number of ionic bonds per cation or anion that actually exists in even the tiniest speck of the salt lattice.
Now, to name a molecule, put the appropriate prefix (1-mono, 2-di, 3-tri, 4-tetra, 5-penta, 6-hexa, 7-hepta, 8-octa, 9-nona, 10-deca) in front of each element in the molecule based on the number of atoms of each element that makes up one single molecule. IF there is ONLY ONE of the first (less electronegative) element in the formula, do NOT use the prefix mono. Notice that you never have called CO2, "monocarbon dioxide" SO DON'T START doing so! However, if you have only one of the second element, you MUST use the "mono" prefix, as in CO is carbon monoxide (notice, in most cases of two of the SAME vowel, you can delete the first vowel, i.e. it's not carbon monooxide).
Since we did not cover naming molecules in G Period, NEITHER Honors class will be tested on naming MOLECULES. The test material will go up to and including naming hydrated salts, hydrates.
Test-taking tip for tomorrow: write out the prefixes for 3=tri and 4=tetra; I DON'T KNOW WHY but, every year, students mix up those two prefixes! That kills me! "Tri" does not look like or even sound like "four"! Immediately AFTER the test begins, write out any other prefixes or facts/info (stored in your short term memory from having looked at your notes BEFORE you enter the classroom) that you are afraid that you might forget during the test.
The test covers all material covered in class since the beginning of the Bonding Unit notes (note: knowledge and mastery of atomic structure and the periodic table is automatically necessary to understand this unit) up to and including naming molecules via the PREFIX system (NOT molecules via the Stock system). Use the notes as a list of objectives.
Don't ever forget (again) : SLOW DOWN when you read each question (and STOP underlining every word in the question, that is WORSE than underlining/identifying no key words and as indiscriminate/useless as underlining no key words!) and make sure that you know exactly and only what is asked for. This will prevent you from (again) writing irrelevant and/or superfluous information. If you do not TAKE PAINS to answer exactly and only what is asked for, you will then (again) run out of time for writing down lines of information that earn you nothing. If you are still unsure about how much to write, do NOT take chances with "how" or "why" questions. Keep asking yourself "how" or "why" and keep writing down info, pictures (with reference), and calculations that support your explanation.
Regents: we did several examples of naming hydrated salts (hydrates) and began the PREFIX system for naming molecules. Tomorrow's multiple choice exam will cover everything that we have done so far in the Bonding Unit up to and including naming molecules via the prefix system.
Make SURE that you have done all of the hw and practice worksheets in preparation for this test. Just as with Honors, the following test-taking tip applies:
For tomorrow: write out the prefixes for 3=tri and 4=tetra; I DON'T KNOW WHY but, every year, students mix up those two prefixes! That kills me! "Tri" does not look like or even sound like "four"! Immediately AFTER the test begins, write out any other prefixes or facts/info (stored in your short term memory from having looked at your notes BEFORE you enter the classroom) that you are afraid that you might forget during the test.
Tip 2: The secret to taking multiple choice tests is to initially IGNORE the answer choices (except for math questions). Work out the solution to the question and then see whether there is a matching answer choice. If there is not, you did something wrong (or, ask me whether you have a misprinted test- it can happen!). If a choice matches your carefully worked out answer, you are likely to have avoided any trap answers and you should be confident about your choice. This assumes that you CAREFULLY read the question and identified the key terms that tell you what is actually being asked for; so, the MOST important test-taking tip on ANY test is to read each question slowly and carefully- even read the question twice, once at a casual speed and the second time at a slower speed.
Good luck tomorrow!
Tomorrow, I will suspend our current unit (intermolecular attractions) and do some of the more difficult problems from Chapters 11 and 12, which are assigned over the break.
I will be putting up a RIDICULOUS number of problems with worked out solutions to help guide you through the two units and, of course, I am an email away, if you need assistance.
Honors: thanks to a couple of students who pointed out a couple of errors on the polyatomic ion worksheet and one error on the salt-naming worksheet. I will correct those errors and post them tonight (on the class webpage, look for the words "updated file" next to the file name.
Today, we went over some of the test-taking errors from the last test. Own your mistakes, (in LIFE, there is seldom better advice than this!), correct them, and learn from them so that you can improve and grow academically.
Then, we reviewed the stock system, which MUST be used for salts of transition metals (very few exceptions: Ag, Cd, Zn salts).
We also learned how to name hydrated salts (HYDRATES) in which there is a certain integer ratio of water molecules embedded in the ionic lattice per formula unit of the salt.
IN D PERIOD but NOT G PERIOD, we finished with the PREFIX system for naming molecules. NO SALTS (except hydrates) HAVE PREFIXES SO, IF YOU EVER SEE A PREFIX IN A FORMULA, YOU MUST BE LOOKING AT THE NAME OF A MOLECULE i.e. carbon dioxide..."di" indicates "must be a molecule". NOTE: unlike salts, there is NO "geometric lattice" of atoms in a molecule; each individual molecule is a separate, unique, individual entity. For example, every separate, individual carbon dioxide molecule has EXACTLY ONE carbon ATOM (double) bonded to TWO oxygen ATOMS, one oxygen atom on either side of the carbon atom. The Lewis structures of molecules show an actual individual molecule but the Lewis structures of salts cannot and do not depict the entire lattice of ions. Lewis structures of salts ONLY show one FORMULA UNIT of the ionic lattice, so Lewis structures of salts cannot possibly depict the true number of ionic bonds per cation or anion that actually exists in even the tiniest speck of the salt lattice.
Now, to name a molecule, put the appropriate prefix (1-mono, 2-di, 3-tri, 4-tetra, 5-penta, 6-hexa, 7-hepta, 8-octa, 9-nona, 10-deca) in front of each element in the molecule based on the number of atoms of each element that makes up one single molecule. IF there is ONLY ONE of the first (less electronegative) element in the formula, do NOT use the prefix mono. Notice that you never have called CO2, "monocarbon dioxide" SO DON'T START doing so! However, if you have only one of the second element, you MUST use the "mono" prefix, as in CO is carbon monoxide (notice, in most cases of two of the SAME vowel, you can delete the first vowel, i.e. it's not carbon monooxide).
Since we did not cover naming molecules in G Period, NEITHER Honors class will be tested on naming MOLECULES. The test material will go up to and including naming hydrated salts, hydrates.
Test-taking tip for tomorrow: write out the prefixes for 3=tri and 4=tetra; I DON'T KNOW WHY but, every year, students mix up those two prefixes! That kills me! "Tri" does not look like or even sound like "four"! Immediately AFTER the test begins, write out any other prefixes or facts/info (stored in your short term memory from having looked at your notes BEFORE you enter the classroom) that you are afraid that you might forget during the test.
The test covers all material covered in class since the beginning of the Bonding Unit notes (note: knowledge and mastery of atomic structure and the periodic table is automatically necessary to understand this unit) up to and including naming molecules via the PREFIX system (NOT molecules via the Stock system). Use the notes as a list of objectives.
Don't ever forget (again) : SLOW DOWN when you read each question (and STOP underlining every word in the question, that is WORSE than underlining/identifying no key words and as indiscriminate/useless as underlining no key words!) and make sure that you know exactly and only what is asked for. This will prevent you from (again) writing irrelevant and/or superfluous information. If you do not TAKE PAINS to answer exactly and only what is asked for, you will then (again) run out of time for writing down lines of information that earn you nothing. If you are still unsure about how much to write, do NOT take chances with "how" or "why" questions. Keep asking yourself "how" or "why" and keep writing down info, pictures (with reference), and calculations that support your explanation.
Regents: we did several examples of naming hydrated salts (hydrates) and began the PREFIX system for naming molecules. Tomorrow's multiple choice exam will cover everything that we have done so far in the Bonding Unit up to and including naming molecules via the prefix system.
Make SURE that you have done all of the hw and practice worksheets in preparation for this test. Just as with Honors, the following test-taking tip applies:
For tomorrow: write out the prefixes for 3=tri and 4=tetra; I DON'T KNOW WHY but, every year, students mix up those two prefixes! That kills me! "Tri" does not look like or even sound like "four"! Immediately AFTER the test begins, write out any other prefixes or facts/info (stored in your short term memory from having looked at your notes BEFORE you enter the classroom) that you are afraid that you might forget during the test.
Tip 2: The secret to taking multiple choice tests is to initially IGNORE the answer choices (except for math questions). Work out the solution to the question and then see whether there is a matching answer choice. If there is not, you did something wrong (or, ask me whether you have a misprinted test- it can happen!). If a choice matches your carefully worked out answer, you are likely to have avoided any trap answers and you should be confident about your choice. This assumes that you CAREFULLY read the question and identified the key terms that tell you what is actually being asked for; so, the MOST important test-taking tip on ANY test is to read each question slowly and carefully- even read the question twice, once at a casual speed and the second time at a slower speed.
Good luck tomorrow!
# posted by C @ 12:25 PM 
