Dear All,
Happy Halloween!
Since most of you are probably too old to go trick-or-treating, I guess you would all have some times to finish up the little assignment that we have for today..
Living Environment 1: HW #16 (Due Tomorrow)
Glencoe: Read pp. 60-64; Do p. 64 Problems #1, 4
Reminder: Unit 3 Exam Next Monday/Tuesday.
Regent Chemistry 1: HW #20 (Due Tomorrow)
Holt: Read pp. 116-122; Do p. 122 Problems #5, 6, 7, 8, 9
Dr. Liu
Wednesday, October 31, 2007
Tuesday, October 30, 2007
Assignment for 10/30/07
Dear All,
Following is the assignment for 10/30/07:
Living Environment 1: HW #15 (Due tomorrow)
1. Draw diagrams to summarize how water, nitrogen, and carbon get recycled throughout the ecosystem (3 diagrams).
2. How is a phosphorous cycle different from water, carbon, and nitrogen cycle?
Regent Chemistry 1: Steam-off... Relax!
Dr. Liu
Following is the assignment for 10/30/07:
Living Environment 1: HW #15 (Due tomorrow)
1. Draw diagrams to summarize how water, nitrogen, and carbon get recycled throughout the ecosystem (3 diagrams).
2. How is a phosphorous cycle different from water, carbon, and nitrogen cycle?
Regent Chemistry 1: Steam-off... Relax!
Dr. Liu
Monday, October 29, 2007
Update for 10/29/07
Dear All,
The following are the information update for today.
For Living Environment 1: No HW today.
For Regent Chemistry 1: Study for Unit #3 Exam tomorrow!
For the answers to questions on the review sheet which we did not get a chance to go over:
6) a) Sr2+ (38)
Proton # = 38 ; Neutron # = 50 ; Electron # = 36 ; Size vs. original atom: Smaller
Electron Configuration of Ion: 2-8-18-8
b) I- (53)
Proton # = 53 ; Neutron # = 74 ; Electron # = 54 ; Size vs. original atom: Bigger
Electron Configuration of Ion: 2-8-18-18-8
c) As3- (33)
Proton # = 33 ; Neutron # = 42 ; Electron # = 36 ; Size vs. original atom: Bigger
Electron Configuration of Ion: 2-8-18-8
• With these information you should be able to draw the atomic structure. Remember, number of protons do not get changed, only the number of electrons. And the electron configuration of the ion is going to be different from that of the atom (because of new # of electrons associated with ions).
7A) John Dalton's atomic model:
- What are the key points of John Dalton’s atomic Model?
1. Each element is composed of indivisible particles called atoms.
2. Atoms of a given element are identical in their physical and chemical properties. Atoms of different element would have different properties.
3. Atoms of different elements combine in simple whole number ratios to form compounds.
4. In chemical reactions, atoms are combined, separated, or rearranged, but they are not created, destroyed, or changed.
- List two ways in which his atomic model had been found to be not true.
1) Atom can be subdivided further into subatomic particles.
2) Presence of Isotopes indicate atoms of same element can have different mass.
7B) J. J. Thomson
- What is his major contribution to atomic theory?
ANS.: He discovered the electron, and proposed plum-pudding model of atom.
- What experiment he did to proved his point? What was result of the experiment? What was his conclusion?
• Experiment: Applied a magnet on a beam in the Cathode Ray Tube under high voltage.
• Results: Regardless of materials of electrodes, the cathode rays bent toward the positive charged side of magnet.
• Conclusion: Since opposite charge attract, this subatomic particles must have negative charge - electrons.
7C) Ernest Rutheford
- What is his major contribution to atomic theory?
Ans.: He discovered the presence of a small, dense, positively charged nucleus. Found that the volume of atoms consists mostly of empty spaces.
- What experiment he did to proved his point? What was result of the experiment? What was his conclusion?
• Experiment Conducted: Bombarded thin gold foils with positively charged alpha particles.
• Results: The alpha particles passed through the gold foil most of the time without change in direction; but ~ 1 out of 10,000 times, it bounced back or was greatly deflected.
• Conclusion:
1) Most part of the atom consists of empty spaces.
2) Atoms must have a small, dense, positively charged nucleus that bounces back the alpha particles without being knocked off the position.
7D) Niels Bohr
- What are key points of Bohr’s atomic model?
1. Electron could only orbit at certain specified distance from the nucleus. Each distance represents a discrete amount of energy that an electron can have.
2. The lowest energy level was called the ground state. Since electrons could not have lower energy than the ground state, it could not come any closer to the nucleus and thus would remain stable.
3. In a given orbit, an electron never radiated or absorbed energy.
4. When an atom absorbed exactly the right amount of energy, the electron would rise to a higher energy level (referred to as excited state). Conversely, if the electron fall from this excited state back to a lower energy level, it would release an energy that would appears as photon of light.
8) Ans. Orbital: a region of space around the nucleus in which there is a high probability of finding the electrons.
- Electrons are represented as electron clouds since there is no distinct orbits, and the probability of finding electrons vary gradually and have no sharp boundary.
9) Ans. When electron absorbs energy to go from the lower energy level to a higher energy level, it is said to make an energy state transition from the ground state to the excited state. Since electrons are unstable in the excited state, it would drop back to the lower energy level and releases photon with energy corresponds to the difference between the two energy levels; this would lead to the formation of characteristic line spectrum. This spectrum is different for each element and thus can be used as a “fingerprint” for the element.
Dr. Liu
The following are the information update for today.
For Living Environment 1: No HW today.
For Regent Chemistry 1: Study for Unit #3 Exam tomorrow!
For the answers to questions on the review sheet which we did not get a chance to go over:
6) a) Sr2+ (38)
Proton # = 38 ; Neutron # = 50 ; Electron # = 36 ; Size vs. original atom: Smaller
Electron Configuration of Ion: 2-8-18-8
b) I- (53)
Proton # = 53 ; Neutron # = 74 ; Electron # = 54 ; Size vs. original atom: Bigger
Electron Configuration of Ion: 2-8-18-18-8
c) As3- (33)
Proton # = 33 ; Neutron # = 42 ; Electron # = 36 ; Size vs. original atom: Bigger
Electron Configuration of Ion: 2-8-18-8
• With these information you should be able to draw the atomic structure. Remember, number of protons do not get changed, only the number of electrons. And the electron configuration of the ion is going to be different from that of the atom (because of new # of electrons associated with ions).
7A) John Dalton's atomic model:
- What are the key points of John Dalton’s atomic Model?
1. Each element is composed of indivisible particles called atoms.
2. Atoms of a given element are identical in their physical and chemical properties. Atoms of different element would have different properties.
3. Atoms of different elements combine in simple whole number ratios to form compounds.
4. In chemical reactions, atoms are combined, separated, or rearranged, but they are not created, destroyed, or changed.
- List two ways in which his atomic model had been found to be not true.
1) Atom can be subdivided further into subatomic particles.
2) Presence of Isotopes indicate atoms of same element can have different mass.
7B) J. J. Thomson
- What is his major contribution to atomic theory?
ANS.: He discovered the electron, and proposed plum-pudding model of atom.
- What experiment he did to proved his point? What was result of the experiment? What was his conclusion?
• Experiment: Applied a magnet on a beam in the Cathode Ray Tube under high voltage.
• Results: Regardless of materials of electrodes, the cathode rays bent toward the positive charged side of magnet.
• Conclusion: Since opposite charge attract, this subatomic particles must have negative charge - electrons.
7C) Ernest Rutheford
- What is his major contribution to atomic theory?
Ans.: He discovered the presence of a small, dense, positively charged nucleus. Found that the volume of atoms consists mostly of empty spaces.
- What experiment he did to proved his point? What was result of the experiment? What was his conclusion?
• Experiment Conducted: Bombarded thin gold foils with positively charged alpha particles.
• Results: The alpha particles passed through the gold foil most of the time without change in direction; but ~ 1 out of 10,000 times, it bounced back or was greatly deflected.
• Conclusion:
1) Most part of the atom consists of empty spaces.
2) Atoms must have a small, dense, positively charged nucleus that bounces back the alpha particles without being knocked off the position.
7D) Niels Bohr
- What are key points of Bohr’s atomic model?
1. Electron could only orbit at certain specified distance from the nucleus. Each distance represents a discrete amount of energy that an electron can have.
2. The lowest energy level was called the ground state. Since electrons could not have lower energy than the ground state, it could not come any closer to the nucleus and thus would remain stable.
3. In a given orbit, an electron never radiated or absorbed energy.
4. When an atom absorbed exactly the right amount of energy, the electron would rise to a higher energy level (referred to as excited state). Conversely, if the electron fall from this excited state back to a lower energy level, it would release an energy that would appears as photon of light.
8) Ans. Orbital: a region of space around the nucleus in which there is a high probability of finding the electrons.
- Electrons are represented as electron clouds since there is no distinct orbits, and the probability of finding electrons vary gradually and have no sharp boundary.
9) Ans. When electron absorbs energy to go from the lower energy level to a higher energy level, it is said to make an energy state transition from the ground state to the excited state. Since electrons are unstable in the excited state, it would drop back to the lower energy level and releases photon with energy corresponds to the difference between the two energy levels; this would lead to the formation of characteristic line spectrum. This spectrum is different for each element and thus can be used as a “fingerprint” for the element.
Dr. Liu
Friday, October 26, 2007
Update for 10/26/07
Dear All,
Now that I have a chance to talk to some of your parents and discuss what had happened during the past marking period, I just want to emphasize a few things:
1. Do your labs: If you don't come to the labs, not only will you get a shoddy course grade, you won't be eligible for Regent exam, and you might have to go to summer school or retake the course over again if you want to graduate. If you had attended the lab., complete your lab. report and hand them in!
2. Homework counts: Some of you overlook this part of the course grade thinking it is unimportant. Your marking period 1 grade should have prove you wrong!
3. Come to class and ready to learn: Your exam and quiz depend on how much you have learned from everything you did in class and at home.
Everyone of you can pass the class if you did all the work to the best of your ability and tried your best to learn. You will enjoy the reward so much more once you give it your best shot and honest efforts.
Now for the weekend update:
Living Environment 1: Finish HW #14 and complete any labs. write-up that is still missing!
Regent Chemistry 1: Work on the review sheet, do your best and we will go over it on Monday. Unit Exam #3 on Tuesday! Also, complete that lab. report #7.
That's all, have a nice weekend!
Dr. Liu
Now that I have a chance to talk to some of your parents and discuss what had happened during the past marking period, I just want to emphasize a few things:
1. Do your labs: If you don't come to the labs, not only will you get a shoddy course grade, you won't be eligible for Regent exam, and you might have to go to summer school or retake the course over again if you want to graduate. If you had attended the lab., complete your lab. report and hand them in!
2. Homework counts: Some of you overlook this part of the course grade thinking it is unimportant. Your marking period 1 grade should have prove you wrong!
3. Come to class and ready to learn: Your exam and quiz depend on how much you have learned from everything you did in class and at home.
Everyone of you can pass the class if you did all the work to the best of your ability and tried your best to learn. You will enjoy the reward so much more once you give it your best shot and honest efforts.
Now for the weekend update:
Living Environment 1: Finish HW #14 and complete any labs. write-up that is still missing!
Regent Chemistry 1: Work on the review sheet, do your best and we will go over it on Monday. Unit Exam #3 on Tuesday! Also, complete that lab. report #7.
That's all, have a nice weekend!
Dr. Liu
Thursday, October 25, 2007
Assignment for 10/25/07
Dear All,
Following is the assignment for 10/25/07:
Living Environment 1: HW #14 (Due Monday 10/29/07):
Glencoe: Read pp. 45~49; Do p. 49 Problems #1, 2, 3.
Reminder: Lab. #6+#7 write-up past due!!!
Regent Chemistry 1: No HW today. Finish up your lab. #7 lab. report (due Monday).
Reminder: Exam next Tuesday (Hmmm... Smells like a conspiracy theory to me...)
Dr. Liu
Following is the assignment for 10/25/07:
Living Environment 1: HW #14 (Due Monday 10/29/07):
Glencoe: Read pp. 45~49; Do p. 49 Problems #1, 2, 3.
Reminder: Lab. #6+#7 write-up past due!!!
Regent Chemistry 1: No HW today. Finish up your lab. #7 lab. report (due Monday).
Reminder: Exam next Tuesday (Hmmm... Smells like a conspiracy theory to me...)
Dr. Liu
Wednesday, October 24, 2007
Assignment for 10/24/2007
Dear All,
The following are the assignments for 10/24/07:
Living Environment 1: HW #13 (Due tomorrow)
1. Compare and contrast a food chain and a food web.
2. If the Sun was to produce less energy and then finally burned out, what effect will it has on the living organisms.
• Reminder: Finish your lab #6~#7 write-up and hand them in!!
Regent Chemistry 1: HW # 19 (Due tomorrow)
Do p. 99 Problems 5, 6, 7.
• Reminder: Start working on your lab. report #7. Exam next Monday.
Dr. Liu
The following are the assignments for 10/24/07:
Living Environment 1: HW #13 (Due tomorrow)
1. Compare and contrast a food chain and a food web.
2. If the Sun was to produce less energy and then finally burned out, what effect will it has on the living organisms.
• Reminder: Finish your lab #6~#7 write-up and hand them in!!
Regent Chemistry 1: HW # 19 (Due tomorrow)
Do p. 99 Problems 5, 6, 7.
• Reminder: Start working on your lab. report #7. Exam next Monday.
Dr. Liu
Tuesday, October 23, 2007
Assignment for 10/23/2007
Dear All,
The following are the assignment for 10/23/07:
Living Environment 1: With our in-class discussion today, I think you can finished the remaining questions for the Lab. #6 and #7 write-up. Complete it for tonight and hand it in tomorrow (Wednesday).
Regent Chemistry 1: HW #18 (Due tomorrow)
Holt - Read pp. 96~99. Do p. 99 Problems 1, 2, 3.
Dr. Liu
The following are the assignment for 10/23/07:
Living Environment 1: With our in-class discussion today, I think you can finished the remaining questions for the Lab. #6 and #7 write-up. Complete it for tonight and hand it in tomorrow (Wednesday).
Regent Chemistry 1: HW #18 (Due tomorrow)
Holt - Read pp. 96~99. Do p. 99 Problems 1, 2, 3.
Dr. Liu
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