Thursday, May 29, 2008
Thurs-Day 2
Bio- Our lab test is on Monday so be ready to finish tomorrow's lab and then to review the second period of our double. I will give you a list of test objectives to study over the weekend. Continue to bring in your review books for the rest of the school year.
We discussed some of the Part D lab questions in the red review book; we mainly focused on the DNA fragment separation technique, gel electrophoresis, which can be used to determine the evolutionary relationships among species and also the genetic relationships among family members or among ethnic groups.
Chem 7/8- we had our Redox unit exam and then we discussed our metal activity series lab.
Chem 9- we had our Redox unit exam today.
We discussed some of the Part D lab questions in the red review book; we mainly focused on the DNA fragment separation technique, gel electrophoresis, which can be used to determine the evolutionary relationships among species and also the genetic relationships among family members or among ethnic groups.
Chem 7/8- we had our Redox unit exam and then we discussed our metal activity series lab.
Chem 9- we had our Redox unit exam today.
# posted by C @ 4:45 PM 
Wednesday, May 28, 2008
Wednes-Day 1
Bio- we did the final NY State Lab on Biodiversity in which we determine the evolutionary relationship between a valuable, endangered plant species and three other plant species.
By looking at various forms of evidence that show evolutionary kinship/relationship or lack thereof, we determined which of the other species is most closely related to Botana curous.
We will do the remaining two and most important tests (gel electrophoresis and amino acid sequencing/enzyme comparison) on Friday. Our exam on the four state labs is on Monday.
Chem 7- we reviewed for tomorrow's Redox and Electrochemistry exam.
Check for annotated review packet solutions online tonight.
I'll be in Room 301 tomorrow morning at about 8:10.
Chem 8/9- we reviewed for tomorrow's Redox and Electrochemistry exam.
We then did some Regents review, using the June 2007 exam.
Check for annotated review packet solutions online tonight.
I'll be in Room 301 tomorrow morning at about 8:10.
By looking at various forms of evidence that show evolutionary kinship/relationship or lack thereof, we determined which of the other species is most closely related to Botana curous.
We will do the remaining two and most important tests (gel electrophoresis and amino acid sequencing/enzyme comparison) on Friday. Our exam on the four state labs is on Monday.
Chem 7- we reviewed for tomorrow's Redox and Electrochemistry exam.
Check for annotated review packet solutions online tonight.
I'll be in Room 301 tomorrow morning at about 8:10.
Chem 8/9- we reviewed for tomorrow's Redox and Electrochemistry exam.
We then did some Regents review, using the June 2007 exam.
Check for annotated review packet solutions online tonight.
I'll be in Room 301 tomorrow morning at about 8:10.
# posted by C @ 1:02 PM
Tues-Day 2
Bio- welcome back from our extended weekend!
Today we discussed the part D section of the LE Regents; part D questions cover the FOUR required state labs. We focused mainly on the Diffusion/Osmosis lab. We defined the processes, gave examples and discussed TRANSPORT, the life process that most frequently involves diffusion.
Chem 7/8- we discussed three applications of electrolytic cells:
the electrolysis of molten salts to produce active metals in their atomic (not cationic) form and active non-metals in their molecular form.
electroplating of a precious (relatively inactive) metal onto an object that consists of a more reactive, cheaper metal.
the electrolysis of water, which decomposes H2O to its elements H2 and O2; these gases can then be stored and used as combustible fuel in H2-powered vehicles.
We then did a lab involving the spontaneous single cationic replacement of various metals.
Chem 9- we discussed three applications of electrolytic cells:
the electrolysis of molten salts to produce active metals in their atomic (not cationic) form and active non-metals in their molecular form.
electroplating of a precious (relatively inactive) metal onto an object that consists of a more reactive, cheaper metal.
the electrolysis of water, which decomposes H2O to its elements H2 and O2; these gases can then be stored and used as combustible fuel in H2-powered vehicles.
Today we discussed the part D section of the LE Regents; part D questions cover the FOUR required state labs. We focused mainly on the Diffusion/Osmosis lab. We defined the processes, gave examples and discussed TRANSPORT, the life process that most frequently involves diffusion.
Chem 7/8- we discussed three applications of electrolytic cells:
the electrolysis of molten salts to produce active metals in their atomic (not cationic) form and active non-metals in their molecular form.
electroplating of a precious (relatively inactive) metal onto an object that consists of a more reactive, cheaper metal.
the electrolysis of water, which decomposes H2O to its elements H2 and O2; these gases can then be stored and used as combustible fuel in H2-powered vehicles.
We then did a lab involving the spontaneous single cationic replacement of various metals.
Chem 9- we discussed three applications of electrolytic cells:
the electrolysis of molten salts to produce active metals in their atomic (not cationic) form and active non-metals in their molecular form.
electroplating of a precious (relatively inactive) metal onto an object that consists of a more reactive, cheaper metal.
the electrolysis of water, which decomposes H2O to its elements H2 and O2; these gases can then be stored and used as combustible fuel in H2-powered vehicles.
# posted by C @ 12:46 AM
Monday, May 26, 2008
Chem HW
Chem classes:
I just want to clarify question 8 in the hw. You are asked to draw and label an electrochemical cell; make that a Voltaic/Galvanic spontaneous cell. Furthermore, the notation used in the question, Fe/Fe 2+//Pb 2+/Pb, means that the two electrodes are Fe metal and Pb metal; these electrodes are dipped in aqueous salt solutions of Fe 2+ and Pb 2+ cations, respectively.
We've covered each hw question type in the notes so you can do them all.
See you on Tuesday!
I just want to clarify question 8 in the hw. You are asked to draw and label an electrochemical cell; make that a Voltaic/Galvanic spontaneous cell. Furthermore, the notation used in the question, Fe/Fe 2+//Pb 2+/Pb, means that the two electrodes are Fe metal and Pb metal; these electrodes are dipped in aqueous salt solutions of Fe 2+ and Pb 2+ cations, respectively.
We've covered each hw question type in the notes so you can do them all.
See you on Tuesday!
# posted by C @ 10:08 AM
Saturday, May 24, 2008
Fri-Day 1
Bio- For the rest of the school year, bring in your Glencoe Living Environment Review books for Regents review in class!
We took our Ecology/Human Impacts exam, which I'll return to you on Wednesday after the makeups are given on Tuesday.
We then began Regents exam review by emphasizing the ULTRA-important test-taking skills that you MUST use on your Regents exam in order to maximize your score and effort.
We dissected each question by 1. topic , 2. key terms, 3. predicted answer, and 4. finding the matching or synonymous answer choice.
I'll post the rest of that Regents on Blackboard so that we can go over it at extra help on Tuesday morning. Complete that test this weekend so that you can identify your strengths and weaknesses; we can efficiently address any questions that were difficult for you.
Chem 7- On Blackboard, check out the link to the interactive Voltaic cell!
We built a spontaneous Voltaic/Galvanic cell, labeled its parts, and explained how the two half reactions were used to generate electricity.
We then built a cell that is the OPPOSITE of a spontaneous cell: the ELECTROLYTIC cell, one that REQUIRES a battery/voltage source in order to CAUSE a nonspontaneous reaction to occur.
However, reduction still occurs at the CATHODE (RED CAT) and oxidation still occurs at the anode BUT the + and - signs are changed in an electrolytic cell (anode is now (+) and cathode is now (-), by definition).
We then saw how to use Table J to predict whether a given reaction is spontaneous or not. If the MORE active (higher on the chart) metal LOSES electrons in the reaction, then the reaction is spontaneous/natural.
Chem 8/9- On Blackboard, check out the link to the interactive Voltaic cell!
We built a spontaneous Voltaic/Galvanic cell, labeled its parts, and explained how the two half reactions were used to generate electricity.
We then built a cell that is the OPPOSITE of a spontaneous cell: the ELECTROLYTIC cell, one that REQUIRES a battery/voltage source in order to CAUSE a nonspontaneous reaction to occur.
However, reduction still occurs at the CATHODE (RED CAT) and oxidation still occurs at the anode BUT the + and - signs are changed in an electrolytic cell (anode is now (+) and cathode is now (-), by definition).
We then saw how to use Table J to predict whether a given reaction is spontaneous or not. If the MORE active (higher on the chart) metal LOSES electrons in the reaction, then the reaction is spontaneous/natural.
We then did a little lab that tested whether the above predictions were observed in practice by performing 6 single replacement reactions.
We took our Ecology/Human Impacts exam, which I'll return to you on Wednesday after the makeups are given on Tuesday.
We then began Regents exam review by emphasizing the ULTRA-important test-taking skills that you MUST use on your Regents exam in order to maximize your score and effort.
We dissected each question by 1. topic , 2. key terms, 3. predicted answer, and 4. finding the matching or synonymous answer choice.
I'll post the rest of that Regents on Blackboard so that we can go over it at extra help on Tuesday morning. Complete that test this weekend so that you can identify your strengths and weaknesses; we can efficiently address any questions that were difficult for you.
Chem 7- On Blackboard, check out the link to the interactive Voltaic cell!
We built a spontaneous Voltaic/Galvanic cell, labeled its parts, and explained how the two half reactions were used to generate electricity.
We then built a cell that is the OPPOSITE of a spontaneous cell: the ELECTROLYTIC cell, one that REQUIRES a battery/voltage source in order to CAUSE a nonspontaneous reaction to occur.
However, reduction still occurs at the CATHODE (RED CAT) and oxidation still occurs at the anode BUT the + and - signs are changed in an electrolytic cell (anode is now (+) and cathode is now (-), by definition).
We then saw how to use Table J to predict whether a given reaction is spontaneous or not. If the MORE active (higher on the chart) metal LOSES electrons in the reaction, then the reaction is spontaneous/natural.
Chem 8/9- On Blackboard, check out the link to the interactive Voltaic cell!
We built a spontaneous Voltaic/Galvanic cell, labeled its parts, and explained how the two half reactions were used to generate electricity.
We then built a cell that is the OPPOSITE of a spontaneous cell: the ELECTROLYTIC cell, one that REQUIRES a battery/voltage source in order to CAUSE a nonspontaneous reaction to occur.
However, reduction still occurs at the CATHODE (RED CAT) and oxidation still occurs at the anode BUT the + and - signs are changed in an electrolytic cell (anode is now (+) and cathode is now (-), by definition).
We then saw how to use Table J to predict whether a given reaction is spontaneous or not. If the MORE active (higher on the chart) metal LOSES electrons in the reaction, then the reaction is spontaneous/natural.
We then did a little lab that tested whether the above predictions were observed in practice by performing 6 single replacement reactions.
# posted by C @ 11:33 AM
Thursday, May 22, 2008
Thurs-Day 2
Bio- HW is due tomorrow BEFORE the test. Use your hw of thoroughly and accurately answering the objectives, WITH EXAMPLES, as a good preparation for what you WILL BE WRITING and SEEING on tomorrow's unit exam.
Today, we reviewed for tomorrow's exam by looking at some of the causes, effects, and solutions to some of the human impacts on the environment. We looked at specific problems of increasing the greenhouse effect (CO2 increase in the atmosphere), destruction of the ozone layer, sewage treatment, and deforestation.
Chem 7/8- we learned how to spot/label the oxidizing AGENT and reducing AGENT in a redox reaction. The oxidizing AGENT causes the OTHER reactant to be OXIDIZED/lose electrons by attracting the electrons away from said different reactant. Thus, good oxidizing agents are very electronegative (non-metals/halogens/oxygen).
The reducing AGENT causes the OTHER reactant to be REDUCED by giving up its electrons to the other reactant.
So, the substance that IS oxidized IS the REDUCING AGENT.
The substance that IS reduced IS the OXIDIZING AGENT.
We then began a discussion on separating a redox reaction into two half-reactions that occur between two separated beakers joined by a wire and a salt bridge. This is a Voltaic or Galvanic electrochemical cell and can generate electricity spontaneously via a chemical redox reaction. The electricity/electrical energy can then be used to power an electrical device (iPod, cell-phone, motor, etc.).
Chem 9- we learned how to spot/label the oxidizing AGENT and reducing AGENT in a redox reaction. The oxidizing AGENT causes the OTHER reactant to be OXIDIZED/lose electrons by attracting the electrons away from said different reactant. Thus, good oxidizing agents are very electronegative (non-metals/halogens/oxygen).
The reducing AGENT causes the OTHER reactant to be REDUCED by giving up its electrons to the other reactant.
So, the substance that IS oxidized IS the REDUCING AGENT.
The substance that IS reduced IS the OXIDIZING AGENT.
We then began a discussion on separating a redox reaction into two half-reactions that occur between two separated beakers joined by a wire and a salt bridge. This is a Voltaic or Galvanic electrochemical cell and can generate electricity spontaneously via a chemical redox reaction. The electricity/electrical energy can then be used to power an electrical device (iPod, cell-phone, motor, etc.).
Today, we reviewed for tomorrow's exam by looking at some of the causes, effects, and solutions to some of the human impacts on the environment. We looked at specific problems of increasing the greenhouse effect (CO2 increase in the atmosphere), destruction of the ozone layer, sewage treatment, and deforestation.
Chem 7/8- we learned how to spot/label the oxidizing AGENT and reducing AGENT in a redox reaction. The oxidizing AGENT causes the OTHER reactant to be OXIDIZED/lose electrons by attracting the electrons away from said different reactant. Thus, good oxidizing agents are very electronegative (non-metals/halogens/oxygen).
The reducing AGENT causes the OTHER reactant to be REDUCED by giving up its electrons to the other reactant.
So, the substance that IS oxidized IS the REDUCING AGENT.
The substance that IS reduced IS the OXIDIZING AGENT.
We then began a discussion on separating a redox reaction into two half-reactions that occur between two separated beakers joined by a wire and a salt bridge. This is a Voltaic or Galvanic electrochemical cell and can generate electricity spontaneously via a chemical redox reaction. The electricity/electrical energy can then be used to power an electrical device (iPod, cell-phone, motor, etc.).
Chem 9- we learned how to spot/label the oxidizing AGENT and reducing AGENT in a redox reaction. The oxidizing AGENT causes the OTHER reactant to be OXIDIZED/lose electrons by attracting the electrons away from said different reactant. Thus, good oxidizing agents are very electronegative (non-metals/halogens/oxygen).
The reducing AGENT causes the OTHER reactant to be REDUCED by giving up its electrons to the other reactant.
So, the substance that IS oxidized IS the REDUCING AGENT.
The substance that IS reduced IS the OXIDIZING AGENT.
We then began a discussion on separating a redox reaction into two half-reactions that occur between two separated beakers joined by a wire and a salt bridge. This is a Voltaic or Galvanic electrochemical cell and can generate electricity spontaneously via a chemical redox reaction. The electricity/electrical energy can then be used to power an electrical device (iPod, cell-phone, motor, etc.).
# posted by C @ 1:48 PM
Wednes-Day 1
Bio- we discussed various ways that humans can negatively impact ecosystems. From deforestation, which reduces the producer/autotroph level of organisms and can cause ecosystem instability, to monoculture farming, the planting of a single type of crop that can deplete the nutrient-rich layer of topsoil of the same essential nutrients so that the soil becomes less and less fertile for plants, we gave several examples of some of the negative effects that humans can and do cause.
Chem 7- we learned how to spot redox reaction by quickly inspecting whether a reaction is a single replacement or synthesis (from elements). We saw that double replacement reactions are NOT redox reactions and that decompositions may or may not be redox reactions.
We also balanced some complex redox reactions via the oxidation number method.
Chem 8/9- we learned how to spot redox reaction by quickly inspecting whether a reaction is a single replacement or synthesis (from elements). We saw that double replacement reactions are NOT redox reactions and that decompositions may or may not be redox reactions.
We also balanced some complex redox reactions via the oxidation number method.
We then finished our acid-base titration lab discussion.
Chem 7- we learned how to spot redox reaction by quickly inspecting whether a reaction is a single replacement or synthesis (from elements). We saw that double replacement reactions are NOT redox reactions and that decompositions may or may not be redox reactions.
We also balanced some complex redox reactions via the oxidation number method.
Chem 8/9- we learned how to spot redox reaction by quickly inspecting whether a reaction is a single replacement or synthesis (from elements). We saw that double replacement reactions are NOT redox reactions and that decompositions may or may not be redox reactions.
We also balanced some complex redox reactions via the oxidation number method.
We then finished our acid-base titration lab discussion.
# posted by C @ 1:40 PM
Wednesday, May 21, 2008
Tues-Day 2
Bio- we discussed some of the ways that humans impact the environment:
by over-hunting and over-fishing, humans have caused the extinction of various species: the dodo-bird, the QUAGGA, one of Africa's most famous extinct animals, was a subspecies of the plains zebra, which was once found in great numbers in South Africa's Cape Province and the southern part of the Orange Free State. It was distinguished from other zebras by having the usual vivid marks on the front part of the body only. The Tasmanian Tiger was hunted to extinction in 1936. The sea cow grew up to 7.9 meters (25.9 ft) long and weighed up to three tons, much larger than the manatee but is now extinct.
By burning fossil fuels, carbon dioxide concentration in the atmosphere increases and can contribute to the greenhouse effect. Also oxides of sulfur and nitrogen, from burning coal and other fuels, can react with water in the air to form acids, which produce acid rain that changes the abiotic factor, pH, of aquatic biomes. This can upset a stable ecosystem.
Chem 7/8- we learned the six-step process for balancing a redox reaction via the "oxidation number" method. Some of these balancing problems are harder than others due to the following factors: elements that have subscripts e.g. Cr2O7 2- must have their mass balanced BEFORE the charge is balanced in a half-reaction; also, the oxidation number assigned to an element with a subscript means that EACH of the atoms of that element have the SAME oxidation number in a given compound e.g. in H2O2, EACH H is +1 and EACH O is -1.
We then finished our discussion of the acid-base titration lab.
Chem 9- we learned the six-step process for balancing a redox reaction via the "oxidation number" method. Some of these balancing problems are harder than others due to the following factors: elements that have subscripts e.g. Cr2O7 2- must have their mass balanced BEFORE the charge is balanced in a half-reaction; also, the oxidation number assigned to an element with a subscript means that EACH of the atoms of that element have the SAME oxidation number in a given compound e.g. in H2O2, EACH H is +1 and EACH O is -1.
by over-hunting and over-fishing, humans have caused the extinction of various species: the dodo-bird, the QUAGGA, one of Africa's most famous extinct animals, was a subspecies of the plains zebra, which was once found in great numbers in South Africa's Cape Province and the southern part of the Orange Free State. It was distinguished from other zebras by having the usual vivid marks on the front part of the body only. The Tasmanian Tiger was hunted to extinction in 1936. The sea cow grew up to 7.9 meters (25.9 ft) long and weighed up to three tons, much larger than the manatee but is now extinct.
By burning fossil fuels, carbon dioxide concentration in the atmosphere increases and can contribute to the greenhouse effect. Also oxides of sulfur and nitrogen, from burning coal and other fuels, can react with water in the air to form acids, which produce acid rain that changes the abiotic factor, pH, of aquatic biomes. This can upset a stable ecosystem.
Chem 7/8- we learned the six-step process for balancing a redox reaction via the "oxidation number" method. Some of these balancing problems are harder than others due to the following factors: elements that have subscripts e.g. Cr2O7 2- must have their mass balanced BEFORE the charge is balanced in a half-reaction; also, the oxidation number assigned to an element with a subscript means that EACH of the atoms of that element have the SAME oxidation number in a given compound e.g. in H2O2, EACH H is +1 and EACH O is -1.
We then finished our discussion of the acid-base titration lab.
Chem 9- we learned the six-step process for balancing a redox reaction via the "oxidation number" method. Some of these balancing problems are harder than others due to the following factors: elements that have subscripts e.g. Cr2O7 2- must have their mass balanced BEFORE the charge is balanced in a half-reaction; also, the oxidation number assigned to an element with a subscript means that EACH of the atoms of that element have the SAME oxidation number in a given compound e.g. in H2O2, EACH H is +1 and EACH O is -1.
# posted by C @ 12:30 PM
Mon-Day 1
Bio- we discussed the meaning of a biological "niche", which is the "role" that an organism plays in an ecosystem; this role includes, for a given species, its habitat, food sources, predator-prey relationships, and general relationships to any biotic and abiotic factors in the habitat.
We saw that species that have the same or similar niches will have increased competition for survival because they consume similar food and live in the same areas.
Chem 7- we discussed the various rules for assigning oxidation numbers; oxidation numbers are assigned so that one can determine which elements lose or gain electrons (or electron density i.e. the electrons get closer to their nuclei) in a chemical reaction.
The oxidation numbers are logical because, for ions, the oxidation number matches the charge of the ion; for atoms, the oxidation numbers are negative for the more electronegative atoms in the compound and positive for the less electronegative elements in the compound.
See Blackboard for answers to all of the worksheet questions.
Chem 8/9- we discussed the various rules for assigning oxidation numbers; oxidation numbers are assigned so that one can determine which elements lose or gain electrons (or electron density i.e. the electrons get closer to their nuclei) in a chemical reaction.
The oxidation numbers are logical because, for ions, the oxidation number matches the charge of the ion; for atoms, the oxidation numbers are negative for the more electronegative atoms in the compound and positive for the less electronegative elements in the compound.
See Blackboard for answers to all of the worksheet questions.
We then discussed the salt hydrolysis lab.
We saw that species that have the same or similar niches will have increased competition for survival because they consume similar food and live in the same areas.
Chem 7- we discussed the various rules for assigning oxidation numbers; oxidation numbers are assigned so that one can determine which elements lose or gain electrons (or electron density i.e. the electrons get closer to their nuclei) in a chemical reaction.
The oxidation numbers are logical because, for ions, the oxidation number matches the charge of the ion; for atoms, the oxidation numbers are negative for the more electronegative atoms in the compound and positive for the less electronegative elements in the compound.
See Blackboard for answers to all of the worksheet questions.
Chem 8/9- we discussed the various rules for assigning oxidation numbers; oxidation numbers are assigned so that one can determine which elements lose or gain electrons (or electron density i.e. the electrons get closer to their nuclei) in a chemical reaction.
The oxidation numbers are logical because, for ions, the oxidation number matches the charge of the ion; for atoms, the oxidation numbers are negative for the more electronegative atoms in the compound and positive for the less electronegative elements in the compound.
See Blackboard for answers to all of the worksheet questions.
We then discussed the salt hydrolysis lab.
# posted by C @ 12:16 PM
Friday, May 16, 2008
Fri-Day 2
Bio- on Blackboard, I posted the first of at least EIGHT Regents that we will take and go over before your 2008 Bio Regents. Don't miss this opportunity to go into the Regents exam PREPARED and CONFIDENT. Complete the Regents so we can go over it at extra help next Tuesday at 8:10AM.
We detailed the differences between primary and secondary succession: primary succession begins on terrain that has no fertile soil, just barren rock; secondary succession begins with the remains of the organisms of the primary succession so that the initial soil is fertile. This leads to the more rapid rate of the secondary succession as compared to that of the primary succession.
We then discussed, from north to south, the world's biomes and the typical, best-adapted species that inhabit each respective biome. We learned that aquatic biomes generally are the most stable due to the limited temperature and pH fluctuations/changes within that biome. Most of the life forms in aquatic biomes (i.e. most of the biodiversity) exists where light can penetrate i.e. the photic zone.
We then saw a few organisms that are adapted to the aphotic zone of the aquatic biomes: bioluminescent organisms. Our luminol demo failed but we will try, try again on Monday.
Chem 7/8- we began our new unit on oxidation-reduction, redox, by defining the processes of oxidation (LOSS of electrons) and reduction (GAIN of electrons) , LEO and GER.
We saw several examples in which we identified the oxidized element and the reduced element.
We also reviewed some of the oxidation number rules.
We then discussed the acid-base titration lab.
Chem 9- we began our new unit on oxidation-reduction, redox, by defining the processes of oxidation (LOSS of electrons) and reduction (GAIN of electrons) , LEO and GER.
We saw several examples in which we identified the oxidized element and the reduced element.
We also reviewed some of the oxidation number rules.
We detailed the differences between primary and secondary succession: primary succession begins on terrain that has no fertile soil, just barren rock; secondary succession begins with the remains of the organisms of the primary succession so that the initial soil is fertile. This leads to the more rapid rate of the secondary succession as compared to that of the primary succession.
We then discussed, from north to south, the world's biomes and the typical, best-adapted species that inhabit each respective biome. We learned that aquatic biomes generally are the most stable due to the limited temperature and pH fluctuations/changes within that biome. Most of the life forms in aquatic biomes (i.e. most of the biodiversity) exists where light can penetrate i.e. the photic zone.
We then saw a few organisms that are adapted to the aphotic zone of the aquatic biomes: bioluminescent organisms. Our luminol demo failed but we will try, try again on Monday.
Chem 7/8- we began our new unit on oxidation-reduction, redox, by defining the processes of oxidation (LOSS of electrons) and reduction (GAIN of electrons) , LEO and GER.
We saw several examples in which we identified the oxidized element and the reduced element.
We also reviewed some of the oxidation number rules.
We then discussed the acid-base titration lab.
Chem 9- we began our new unit on oxidation-reduction, redox, by defining the processes of oxidation (LOSS of electrons) and reduction (GAIN of electrons) , LEO and GER.
We saw several examples in which we identified the oxidized element and the reduced element.
We also reviewed some of the oxidation number rules.
# posted by C @ 12:52 PM
Thurs-Day 1
Bio- we discussed primary and secondary ecological succession and showed that as communities develop in a particular environment, the soil becomes more and more fertile; the soil can then support more and larger types of plants/trees so a progression is seen over time as communities that are initially dominated by grasses then become dominated by shrubs, then smaller trees, and finally larger trees in the climax community. If a climax community is wiped out by fire or volcano, the resulting land will still contain relatively fertile soil from the debris/aftermath of the fire. Thus, a secondary succession can develop and will develop faster than did the primary succession.
We also saw the effects of exponential human population growth: its depletion of limited resources, an increase and then a decrease in the world food supply, and an increase in overall pollution levels. This necessarily leads to more competition (sometimes WAR) within the species for habitable land and available resources.
Chem 7- we took the acid/base/salt unit exam
Chem 8/9- we took the acid/base/salt unit exam and then we discussed the salt hydrolysis lab.
We also saw the effects of exponential human population growth: its depletion of limited resources, an increase and then a decrease in the world food supply, and an increase in overall pollution levels. This necessarily leads to more competition (sometimes WAR) within the species for habitable land and available resources.
Chem 7- we took the acid/base/salt unit exam
Chem 8/9- we took the acid/base/salt unit exam and then we discussed the salt hydrolysis lab.
# posted by C @ 7:11 AM
Wednesday, May 14, 2008
Wednes-Day 2
Bio- we can begin Regents Review starting tomorrow! I'll hand out our schedule in class tomorrow but, if you would like to come to extra help tomorrow morning, I'll focus on Section 7: Evolution in our red/Glencoe review book; I will try to cover the questions from page 103 to page 110. You may want to preview that section so that we can immediately cover the questions that are more difficult for you.
We did a worksheet on the Carbon Cycle (see Blackboard); we'll get to the Nitrogen Cycle worksheet tomorrow. We saw that the TWO major sources of CO2 on Earth are the atmospheric carbon dioxide and also the dissolved carbon dioxide in the oceans. The CO2 balance is maintained via the "opposite" processes of respiration (produces CO2) and photosynthesis (consumes CO2).
We then discussed ECOLOGICAL SUCCESSION which shows the various stages of development of an ecological community of plants from simple grasses to, over time, shrubs and eventually to a final, stable CLIMAX COMMMUNITY of trees. The types of plants in a climax community depends on the level and types of abiotic factors and climate of its ecosystem.
Chem 7/8- we prepped/reviewed for tomorrow's Acids/Bases/Salts exam. The rest of the problems, including an extra question on indicators is posted on Blackboard. Later, I should have the annotated review packet posted.
We finished discussing the salt hydrolysis lab.
Chem 9- we prepped/reviewed for tomorrow's Acids/Bases/Salts exam. The rest of the problems, including an extra question on indicators is posted on Blackboard. Later, I should have the annotated review packet posted.
We did a worksheet on the Carbon Cycle (see Blackboard); we'll get to the Nitrogen Cycle worksheet tomorrow. We saw that the TWO major sources of CO2 on Earth are the atmospheric carbon dioxide and also the dissolved carbon dioxide in the oceans. The CO2 balance is maintained via the "opposite" processes of respiration (produces CO2) and photosynthesis (consumes CO2).
We then discussed ECOLOGICAL SUCCESSION which shows the various stages of development of an ecological community of plants from simple grasses to, over time, shrubs and eventually to a final, stable CLIMAX COMMMUNITY of trees. The types of plants in a climax community depends on the level and types of abiotic factors and climate of its ecosystem.
Chem 7/8- we prepped/reviewed for tomorrow's Acids/Bases/Salts exam. The rest of the problems, including an extra question on indicators is posted on Blackboard. Later, I should have the annotated review packet posted.
We finished discussing the salt hydrolysis lab.
Chem 9- we prepped/reviewed for tomorrow's Acids/Bases/Salts exam. The rest of the problems, including an extra question on indicators is posted on Blackboard. Later, I should have the annotated review packet posted.
# posted by C @ 12:56 PM
Tuesday, May 13, 2008
Tues-Day 1
Bio- we discussed food chains and food webs and explained the possible outcomes of a disturbance to a food web. If one population in a community decreases or goes extinct, some populations in the community can be adversely affected and other populations may temporarily benefit.
We discussed the concept of an energy pyramid and a biomass pyramid. Both pyramids exhibit the same thing: the organisms that make up the largest (base) part of the pyramid are the PRODUCERS because only producers can photosynthesize their own food (i.e. they are autotrophs) from abundant, simple inorganic molecules such as carbon dioxide and water. Each subsequent level of consumer has less total energy and mass because most of the energy and mass consumed is then lost as heat/energy.
We also discussed biomagnification, which is the concentration of non-degradable contaminants or pollutants as they are passed from the producer level through the consumer levels.
We then continued to discuss the "beaks of finches/natural selection" lab.
Chem 7- I put a LOT of review worksheets and practice tests on Blackboard; review them before your test on Thursday.
We discussed and did examples involving pH and hydronium ion concentrations. We learned how to estimate pH from H+ ion concentrations by focusing on the EXPONENT of the concentration. For example, if the [H+] = 2.0 x 10-4, then the pH MUST be between 3 and 4 (because the exponent is -4) and is likely near 3.8.
We filled out a pH and pOH chart, which you can use to help with pH calculations on your test if you can quickly draw out the pattern.
We also saw the all-important feature of pH that a change of 1.0 pH unit is a TEN-fold change in H+ concentration or "acidity"! So, a change of 2 pH units is a 100x change, a change of 3 pH units is a 1000x change, a change of 4 pH units is a 10000x change (note that the number of zeroes equals the number of pH units changed!).
We then reviewed some Bronsted acid/base concepts and problems.
Chem 8/9- I put a LOT of review worksheets and practice tests on Blackboard; review them before your test on Thursday.
We discussed and did examples involving pH and hydronium ion concentrations. We learned how to estimate pH from H+ ion concentrations by focusing on the EXPONENT of the concentration. For example, if the [H+] = 2.0 x 10-4, then the pH MUST be between 3 and 4 (because the exponent is -4) and is likely near 3.8.
We filled out a pH and pOH chart, which you can use to help with pH calculations on your test if you can quickly draw out the pattern.
We also saw the all-important feature of pH that a change of 1.0 pH unit is a TEN-fold change in H+ concentration or "acidity"! So, a change of 2 pH units is a 100x change, a change of 3 pH units is a 1000x change, a change of 4 pH units is a 10000x change (note that the number of zeroes equals the number of pH units changed!).
We then reviewed some Bronsted acid/base concepts and problems.
We performed an acid-base titration in lab; we will apply the titration formula to our data in order to determine the molarity of the acid that we titrated with .60M NaOH (aq).
We discussed the concept of an energy pyramid and a biomass pyramid. Both pyramids exhibit the same thing: the organisms that make up the largest (base) part of the pyramid are the PRODUCERS because only producers can photosynthesize their own food (i.e. they are autotrophs) from abundant, simple inorganic molecules such as carbon dioxide and water. Each subsequent level of consumer has less total energy and mass because most of the energy and mass consumed is then lost as heat/energy.
We also discussed biomagnification, which is the concentration of non-degradable contaminants or pollutants as they are passed from the producer level through the consumer levels.
We then continued to discuss the "beaks of finches/natural selection" lab.
Chem 7- I put a LOT of review worksheets and practice tests on Blackboard; review them before your test on Thursday.
We discussed and did examples involving pH and hydronium ion concentrations. We learned how to estimate pH from H+ ion concentrations by focusing on the EXPONENT of the concentration. For example, if the [H+] = 2.0 x 10-4, then the pH MUST be between 3 and 4 (because the exponent is -4) and is likely near 3.8.
We filled out a pH and pOH chart, which you can use to help with pH calculations on your test if you can quickly draw out the pattern.
We also saw the all-important feature of pH that a change of 1.0 pH unit is a TEN-fold change in H+ concentration or "acidity"! So, a change of 2 pH units is a 100x change, a change of 3 pH units is a 1000x change, a change of 4 pH units is a 10000x change (note that the number of zeroes equals the number of pH units changed!).
We then reviewed some Bronsted acid/base concepts and problems.
Chem 8/9- I put a LOT of review worksheets and practice tests on Blackboard; review them before your test on Thursday.
We discussed and did examples involving pH and hydronium ion concentrations. We learned how to estimate pH from H+ ion concentrations by focusing on the EXPONENT of the concentration. For example, if the [H+] = 2.0 x 10-4, then the pH MUST be between 3 and 4 (because the exponent is -4) and is likely near 3.8.
We filled out a pH and pOH chart, which you can use to help with pH calculations on your test if you can quickly draw out the pattern.
We also saw the all-important feature of pH that a change of 1.0 pH unit is a TEN-fold change in H+ concentration or "acidity"! So, a change of 2 pH units is a 100x change, a change of 3 pH units is a 1000x change, a change of 4 pH units is a 10000x change (note that the number of zeroes equals the number of pH units changed!).
We then reviewed some Bronsted acid/base concepts and problems.
We performed an acid-base titration in lab; we will apply the titration formula to our data in order to determine the molarity of the acid that we titrated with .60M NaOH (aq).
# posted by C @ 3:06 PM
Monday, May 12, 2008
Mon-Day 2
Bio- we discussed the flow of energy among organisms in an ecosystem. This energy flow is easily seen in a food web. A food web uses arrows to show the flow of energy, which is stored in the molecules that make up the organism, from producers (plants and algae) to primary consumers (herbivores) to secondary consumers to tertiary consumers and sometimes even beyond that.
Going from producer level to primary consumer level and beyond, the total energy of each subsequent level decreases due to the fact that 90% of the energy consumed is lost/released as heat so only 10% can be stored as potential energy in the molecules that makeup the organisms in a given level.
Chem 7/8- we did an acid-base titration using burets, Ehrlenmeyer flasks, and phenolphthalein indicator. We then learned how to use titration data to determine the molarity of an unknown acid or base solution. The important thing to include in our "voom-voom" formula is to include the number of H+ ions available to react per mole of acid and the number of OH- ions available to react per mole of base.
We defined pH and pOH from which we will develop a pH chart that relates acid and base concentrations to pH.
Chem 9- We learned how to use titration data to determine the molarity of an unknown acid or base solution. The important thing to include in our "voom-voom" formula is to include the number of H+ ions available to react per mole of acid and the number of OH- ions available to react per mole of base.
We began to define pH from which we will develop a pH chart that relates acid and base concentrations to pH.
Going from producer level to primary consumer level and beyond, the total energy of each subsequent level decreases due to the fact that 90% of the energy consumed is lost/released as heat so only 10% can be stored as potential energy in the molecules that makeup the organisms in a given level.
Chem 7/8- we did an acid-base titration using burets, Ehrlenmeyer flasks, and phenolphthalein indicator. We then learned how to use titration data to determine the molarity of an unknown acid or base solution. The important thing to include in our "voom-voom" formula is to include the number of H+ ions available to react per mole of acid and the number of OH- ions available to react per mole of base.
We defined pH and pOH from which we will develop a pH chart that relates acid and base concentrations to pH.
Chem 9- We learned how to use titration data to determine the molarity of an unknown acid or base solution. The important thing to include in our "voom-voom" formula is to include the number of H+ ions available to react per mole of acid and the number of OH- ions available to react per mole of base.
We began to define pH from which we will develop a pH chart that relates acid and base concentrations to pH.
# posted by C @ 2:31 PM
Friday, May 9, 2008
Fri-Day 1
Bio- we saw more examples of environmental ABIOTIC (non-living) factors. We then defined CARRYING CAPACITY of an environment as the maximum number (capacity) of members of a given POPULATION that an environment can "carry"/support. The FINITE or limited quantity of abiotic factors in an environment directly determines the carrying capacity of, for example, polar bears in their environment. The other determinants of carrying capacity are the BIOTIC factors i.e. the other populations that make up the community, their actions, their wastes, etc.
We looked at the types of nutritional relationships that are possible in an ecosystem. AUTOTROPHS merely require inorganic abiotic factors (like CO2 and H2O) and an energy source (sunlight) to make carbohydrates and other important macromolecules; autotrophs make their own nutrition. Plants and algae are the main autotrophs on Earth. HETEROTROPHS depend on other organisms as sources of their nutrition. There are four main categories of heterotrophs: carnivores (meat-eaters), herbivores (plant eaters), omnivores, and saprophytes (live off of dead plants and animals).
We also discussed possible SYMBIOTIC relationships between pairs of populations in a community:
commensalism: +, o (win-draw)
mutualism: +, + (win-win)
parasitism: +, - (win-lose)
We then finished our peppered-moth lab discussion and continued working on our finch-beak selection lab.
We looked at the types of nutritional relationships that are possible in an ecosystem. AUTOTROPHS merely require inorganic abiotic factors (like CO2 and H2O) and an energy source (sunlight) to make carbohydrates and other important macromolecules; autotrophs make their own nutrition. Plants and algae are the main autotrophs on Earth. HETEROTROPHS depend on other organisms as sources of their nutrition. There are four main categories of heterotrophs: carnivores (meat-eaters), herbivores (plant eaters), omnivores, and saprophytes (live off of dead plants and animals).
We also discussed possible SYMBIOTIC relationships between pairs of populations in a community:
commensalism: +, o (win-draw)
mutualism: +, + (win-win)
parasitism: +, - (win-lose)
We then finished our peppered-moth lab discussion and continued working on our finch-beak selection lab.
# posted by C @ 12:11 PM
Thurs-Day 2
Bio- we began our Ecology unit by looking at the interaction among various populations in a COMMUNITY and between each population and its environment. We defined and gave examples of: organism, population, community, ecosystem, and biome. We then looked at the four necessary factors to maintain a stable ecosystem.
We then focused on some of the ABIOTIC (NON-living) factors that affect an ecosystem.
Chem 7/8- we did several examples of Bronsted acid-base neutralization reactions. In each reaction, we matched up the conjugate acid-base pairs and noted:
1. the acid and base of a conjugate pair look very similar and differ by ONLY ONE H+ !!!
2. a conjugate acid BECOMES its conjugate base partner by DONATING/LOSING an H+, therefore the acid-base conjugate pair MUST differ by only one H+.
3. a conjugate base BECOMES its conjugate base partner by ACCEPTING/GAINING an H+, therefore the acid-base conjugate pair MUST differ by only one H+.
4. the STRONGER a conjugate acid is, the WEAKER its conjugate base must be.
5. as a reaction proceeds towards equilibrium, there is a shift FROM the stronger acid/stronger base side TOWARDS the weaker acid/weaker base side. Thus, at equilibrium, the concentrations of the weaker acid and weaker base should be higher than the concentrations of the stronger acid
and stronger base.
We also looked at substances that, depending on what substance they are reacting with, can EITHER donate an H+/be a Bronsted acid OR accept an H+/be a Bronsted base; these substances are called AMPHOTERIC (also called) AMPHIPROTIC substances.
We then continued our acidic/basic/neutral salt lab discussion.
Chem 9- we did several examples of Bronsted acid-base neutralization reactions. In each reaction, we matched up the conjugate acid-base pairs and noted:
1. the acid and base of a conjugate pair look very similar and differ by ONLY ONE H+ !!!
2. a conjugate acid BECOMES its conjugate base partner by DONATING/LOSING an H+, therefore the acid-base conjugate pair MUST differ by only one H+.
3. a conjugate base BECOMES its conjugate base partner by ACCEPTING/GAINING an H+, therefore the acid-base conjugate pair MUST differ by only one H+.
4. the STRONGER a conjugate acid is, the WEAKER its conjugate base must be.
5. as a reaction proceeds towards equilibrium, there is a shift FROM the stronger acid/stronger base side TOWARDS the weaker acid/weaker base side. Thus, at equilibrium, the concentrations of the weaker acid and weaker base should be higher than the concentrations of the stronger acid and stronger base.
We also looked at substances that, depending on what substance they are reacting with, can EITHER donate an H+/be a Bronsted acid OR accept an H+/be a Bronsted base; these substances are called AMPHOTERIC (also called) AMPHIPROTIC substances.
We then focused on some of the ABIOTIC (NON-living) factors that affect an ecosystem.
Chem 7/8- we did several examples of Bronsted acid-base neutralization reactions. In each reaction, we matched up the conjugate acid-base pairs and noted:
1. the acid and base of a conjugate pair look very similar and differ by ONLY ONE H+ !!!
2. a conjugate acid BECOMES its conjugate base partner by DONATING/LOSING an H+, therefore the acid-base conjugate pair MUST differ by only one H+.
3. a conjugate base BECOMES its conjugate base partner by ACCEPTING/GAINING an H+, therefore the acid-base conjugate pair MUST differ by only one H+.
4. the STRONGER a conjugate acid is, the WEAKER its conjugate base must be.
5. as a reaction proceeds towards equilibrium, there is a shift FROM the stronger acid/stronger base side TOWARDS the weaker acid/weaker base side. Thus, at equilibrium, the concentrations of the weaker acid and weaker base should be higher than the concentrations of the stronger acid
and stronger base.
We also looked at substances that, depending on what substance they are reacting with, can EITHER donate an H+/be a Bronsted acid OR accept an H+/be a Bronsted base; these substances are called AMPHOTERIC (also called) AMPHIPROTIC substances.
We then continued our acidic/basic/neutral salt lab discussion.
Chem 9- we did several examples of Bronsted acid-base neutralization reactions. In each reaction, we matched up the conjugate acid-base pairs and noted:
1. the acid and base of a conjugate pair look very similar and differ by ONLY ONE H+ !!!
2. a conjugate acid BECOMES its conjugate base partner by DONATING/LOSING an H+, therefore the acid-base conjugate pair MUST differ by only one H+.
3. a conjugate base BECOMES its conjugate base partner by ACCEPTING/GAINING an H+, therefore the acid-base conjugate pair MUST differ by only one H+.
4. the STRONGER a conjugate acid is, the WEAKER its conjugate base must be.
5. as a reaction proceeds towards equilibrium, there is a shift FROM the stronger acid/stronger base side TOWARDS the weaker acid/weaker base side. Thus, at equilibrium, the concentrations of the weaker acid and weaker base should be higher than the concentrations of the stronger acid and stronger base.
We also looked at substances that, depending on what substance they are reacting with, can EITHER donate an H+/be a Bronsted acid OR accept an H+/be a Bronsted base; these substances are called AMPHOTERIC (also called) AMPHIPROTIC substances.
# posted by C @ 6:41 AM
Wednesday, May 7, 2008
Wednes-Day 1
Bio- took the Evolution unit exam today and we followed that up with a discussion of our peppered-moth lab activity. Tomorrow, we begin our unit on Ecology.
Chem 7- we did many examples of determining the acidity, basicity, or neutrality of salts.
We then defined and looked at examples of Arrhenius acids and bases as well as Bronsted-Lowry acids and bases.
Chem 8/9- we did many examples of determining the acidity, basicity, or neutrality of salts.
We then defined and looked at examples of Arrhenius acids and bases as well as Bronsted-Lowry acids and bases.
We then did a lab investigation of the acidic, basic, or neutral properties of a given salt.
Chem 7- we did many examples of determining the acidity, basicity, or neutrality of salts.
We then defined and looked at examples of Arrhenius acids and bases as well as Bronsted-Lowry acids and bases.
Chem 8/9- we did many examples of determining the acidity, basicity, or neutrality of salts.
We then defined and looked at examples of Arrhenius acids and bases as well as Bronsted-Lowry acids and bases.
We then did a lab investigation of the acidic, basic, or neutral properties of a given salt.
# posted by C @ 7:50 PM
Tuesday, May 6, 2008
Tues-Day 2
Bio- we reviewed for tomorrow's Evolution exam. We discussed the five fields of science from which supporting evidence for the Theory of Evolution is found: Comparative Anatomy, Comparative Embryology, Biochemistry, Geology/Archaeology/Fossil Record, and Comparative Cytology. We reviewed evolutionary trees as a means to see evolutionary relationships as well as the natural EXTINCTION of species that occur when that species' traits lose their adaptive value in a changed environment or when the species is out-competed by other species.
We reviewed how a dichotomous key (see Blackboard for all answers) is used to help classify various organisms by using a series of yes/no questions.
We discussed divergent evolution which sees species separate and evolve in very different environments with different selecting agents (which can lead to homologous structures in species that had a common ancestor) and convergent evolution (which can lead to analogous structures in species that are not closely related) due to similar environmental selecting agents.
I'll post some more worksheets by this evening. Study, review, practice writing the FOUR scenarios that show evolution via natural or via artificial selection: peppered moth, antibiotic resistance in bacteria, insecticide resistance in insects, and necks of giraffes.
Chem 7/8- we reviewed the naming of acids and then drew out several acid-base neutralization reactions to see whether a given salt is acidic, basic, or neutral.
Doing so requires the knowledge of the 6 strong acids and the 8 strong bases.
We then did a lab procedure that experimentally determined the acidity, basicity, or neutrality of six different salts.
Chem 9-we reviewed the naming of acids and then drew out and balanced several acid-base neutralization reactions. We later used these neutralization reactions to see whether a given salt is acidic, basic, or neutral.
Doing so requires the knowledge of the 6 strong acids and the 8 strong bases.
We reviewed how a dichotomous key (see Blackboard for all answers) is used to help classify various organisms by using a series of yes/no questions.
We discussed divergent evolution which sees species separate and evolve in very different environments with different selecting agents (which can lead to homologous structures in species that had a common ancestor) and convergent evolution (which can lead to analogous structures in species that are not closely related) due to similar environmental selecting agents.
I'll post some more worksheets by this evening. Study, review, practice writing the FOUR scenarios that show evolution via natural or via artificial selection: peppered moth, antibiotic resistance in bacteria, insecticide resistance in insects, and necks of giraffes.
Chem 7/8- we reviewed the naming of acids and then drew out several acid-base neutralization reactions to see whether a given salt is acidic, basic, or neutral.
Doing so requires the knowledge of the 6 strong acids and the 8 strong bases.
We then did a lab procedure that experimentally determined the acidity, basicity, or neutrality of six different salts.
Chem 9-we reviewed the naming of acids and then drew out and balanced several acid-base neutralization reactions. We later used these neutralization reactions to see whether a given salt is acidic, basic, or neutral.
Doing so requires the knowledge of the 6 strong acids and the 8 strong bases.
# posted by C @ 2:12 PM
Monday, May 5, 2008
Mon-Day 1
Bio- EXTRA HELP REVIEW for Wednesday's EVOLUTION EXAM will be at the usual TUESDAY morning session in Room 301 from about 8:10AM to 8:55 AM; bring your review books to that session; remember, teachers have a meeting on Wednesday morning so you won't be able to get last minute help on Wednesday.
As discussed in class, unit HW is due on Wednesday; either outline sections 15.1 and 15.2 OR answer the section review questions on pages 418 and 419 - for CREDIT, accurate and detailed answers are required; use COMPLETE sentences and paragraphs for any written response answers; you MAY skip question 13.
We discussed the two competing hypotheses that account for/explain the rate of evolution.
GRADUALISM explains that newer species evolve from common ancestor species very slowly, with small changes in genotype and phenotype over long periods of time. The mechanism for this would be a combination of mutation, genetic recombination (sexual reproduction), and genetic drift.
However, the FOSSIL RECORD doesn't always contain fossils that show such slow, gradual change with tiny differences in phenotypes between ancestor and descendant (newer) species.
Thus, an alternative hypothesis, PUNCTUATED EQUILIBRIUM, was introduced to explain the relatively large changes in the fossil record over relatively brief (only a million years or so) period of time. PE explains that, when there has been a drastic change in the environment, there can be drastic changes in the selecting agents so that the favored varieties/best adapted members of a population change rapidly. This can lead to more rapid speciation. The weakness of PE is that it cannot provide a complete mechanism for the rapid speciation given that the rate of non-harmful or non-lethal mutation is slow for most species.
Chem 7- we discussed other acid and base characteristics: they are both electrolytes (the SIX strong acids are strong electrolytes and the EIGHT strong bases are strong electrolytes) and they react with each other to form a salt and water.
We learned how to name acids: there are ONLY seven BINARY acids and each name begins with "HYDRO" followed by the one or two syllable root of the element and then "-IC ACID"; for example HCl is HYDRO-CHLOR-IC ACID.
For ternary acids, if the polyatomic ion formed from the acid ends in "ATE", change the "ATE" to "-IC ACID" and that's IT! For example, NO3 - is nitrATE, so HNO3 is nitrIC acid.
IF the polyatomic ion formed from the acid ends in "ITE", change the "ITE" to "-OUS ACID" and that's it! For example, NO2- is nitrITE, so HNO2 is nitrOUS acid !!!
Chem 8/9- we covered some more characteristics of bases i.e. litmus from red to blue and then we discussed a common characteristic of both acids and bases: they are both electrolytes (the SIX strong acids are strong electrolytes and the EIGHT strong bases are strong electrolytes).
We learned how to name acids: there are ONLY seven BINARY acids and each name begins with "HYDRO" followed by the one or two syllable root of the element and then "-IC ACID"; for example HCl is HYDRO-CHLOR-IC ACID.
For ternary acids, if the polyatomic ion formed from the acid ends in "ATE", change the "ATE" to "-IC ACID" and that's IT! For example, NO3 - is nitrATE, so HNO3 is nitrIC acid.
IF the polyatomic ion formed from the acid ends in "ITE", change the "ITE" to "-OUS ACID" and that's it! For example, NO2- is nitrITE, so HNO2 is nitrOUS acid !!!
We then discussed our precipitate lab and wrote out the net ionic reactions that occurred.
As discussed in class, unit HW is due on Wednesday; either outline sections 15.1 and 15.2 OR answer the section review questions on pages 418 and 419 - for CREDIT, accurate and detailed answers are required; use COMPLETE sentences and paragraphs for any written response answers; you MAY skip question 13.
We discussed the two competing hypotheses that account for/explain the rate of evolution.
GRADUALISM explains that newer species evolve from common ancestor species very slowly, with small changes in genotype and phenotype over long periods of time. The mechanism for this would be a combination of mutation, genetic recombination (sexual reproduction), and genetic drift.
However, the FOSSIL RECORD doesn't always contain fossils that show such slow, gradual change with tiny differences in phenotypes between ancestor and descendant (newer) species.
Thus, an alternative hypothesis, PUNCTUATED EQUILIBRIUM, was introduced to explain the relatively large changes in the fossil record over relatively brief (only a million years or so) period of time. PE explains that, when there has been a drastic change in the environment, there can be drastic changes in the selecting agents so that the favored varieties/best adapted members of a population change rapidly. This can lead to more rapid speciation. The weakness of PE is that it cannot provide a complete mechanism for the rapid speciation given that the rate of non-harmful or non-lethal mutation is slow for most species.
Chem 7- we discussed other acid and base characteristics: they are both electrolytes (the SIX strong acids are strong electrolytes and the EIGHT strong bases are strong electrolytes) and they react with each other to form a salt and water.
We learned how to name acids: there are ONLY seven BINARY acids and each name begins with "HYDRO" followed by the one or two syllable root of the element and then "-IC ACID"; for example HCl is HYDRO-CHLOR-IC ACID.
For ternary acids, if the polyatomic ion formed from the acid ends in "ATE", change the "ATE" to "-IC ACID" and that's IT! For example, NO3 - is nitrATE, so HNO3 is nitrIC acid.
IF the polyatomic ion formed from the acid ends in "ITE", change the "ITE" to "-OUS ACID" and that's it! For example, NO2- is nitrITE, so HNO2 is nitrOUS acid !!!
Chem 8/9- we covered some more characteristics of bases i.e. litmus from red to blue and then we discussed a common characteristic of both acids and bases: they are both electrolytes (the SIX strong acids are strong electrolytes and the EIGHT strong bases are strong electrolytes).
We learned how to name acids: there are ONLY seven BINARY acids and each name begins with "HYDRO" followed by the one or two syllable root of the element and then "-IC ACID"; for example HCl is HYDRO-CHLOR-IC ACID.
For ternary acids, if the polyatomic ion formed from the acid ends in "ATE", change the "ATE" to "-IC ACID" and that's IT! For example, NO3 - is nitrATE, so HNO3 is nitrIC acid.
IF the polyatomic ion formed from the acid ends in "ITE", change the "ITE" to "-OUS ACID" and that's it! For example, NO2- is nitrITE, so HNO2 is nitrOUS acid !!!
We then discussed our precipitate lab and wrote out the net ionic reactions that occurred.
# posted by C @ 2:04 PM
Friday, May 2, 2008
Fri-Day 2
Bio- we looked at some of the causes of variation that can lead to speciation. We recalled how mutation and genetic recombination of alleles via sexual reproduction cause variation within a species. If a relatively SMALL group of members of a species migrates to a new environment with different conditions/"selecting agents"/ "selection pressures", then "GENETIC DRIFT" is likely to occur. Genetic drift is a relatively large change in the frequency/percentage of an allele within the population and this occurs often when only a few of a small group of members are the only ones reproducing. Since the allele percentages rapidly change in just a few generations, evolution rapidly occurred.
If genetic drift occurs due to GEOGRAPHIC ISOLATION, the migrated population that is relatively rapidly evolving MAY become a separate species from the original (non-migrating) population because they can no longer interbreed due to the evolutionary changes between the two populations.
REPRODUCTIVE ISOLATION has occurred when the members of a migrating species have evolved away from the original population to such a degree that they can no longer interbreed due to physical, behavioral (mating "signals"), or genetic differences that had gradually accumulated.
Chem 7/8- we discussed other characteristics of acids and then we discussed bases.
We then did an activity that showed the range of three colors that each acid-base indicator can have depending on the pH of the aqueous solution.
Chem 9- we discussed other characteristics of acids and then we discussed bases.
If genetic drift occurs due to GEOGRAPHIC ISOLATION, the migrated population that is relatively rapidly evolving MAY become a separate species from the original (non-migrating) population because they can no longer interbreed due to the evolutionary changes between the two populations.
REPRODUCTIVE ISOLATION has occurred when the members of a migrating species have evolved away from the original population to such a degree that they can no longer interbreed due to physical, behavioral (mating "signals"), or genetic differences that had gradually accumulated.
Chem 7/8- we discussed other characteristics of acids and then we discussed bases.
We then did an activity that showed the range of three colors that each acid-base indicator can have depending on the pH of the aqueous solution.
Chem 9- we discussed other characteristics of acids and then we discussed bases.
# posted by C @ 1:38 PM
Thursday, May 1, 2008
Thurs-Day 1
Bio - due by TUESDAY, outline the text sections 15.1 and 15.2 (two separate hw credits).
Today we further discussed the modern Theory of Evolution; we saw how evolution in species can be measured/defined as a change in the percentage/frequency of the various alleles in the GENE POOL of a species population. The change in allele frequency is caused by natural selection by the environment for those members of a population whose alleles give them a phenotype that is advantageous to their survival and reproduction in their environment. Thus, the surviving/reproducing members will pass on these advantageous alleles to their offspring, which will have a higher percentage of those alleles in the population.
Chem 7- we began our acid-base unit by discussing some characteristics of acids. We saw that acids are sour, react with ACTIVE metals to form aqueous salt solutions and hydrogen gas, and that acids are molecules that ionize in water to form H3O+, hydronium ion, which is often abbreviated as H+, the aqueous hydrogen ion.
Chem 8/9-we began our acid-base unit by discussing some characteristics of acids. We saw that acids are sour, react with ACTIVE metals to form aqueous salt solutions and hydrogen gas, and that acids are molecules that ionize in water to form H3O+, hydronium ion, which is often abbreviated as H+, the aqueous hydrogen ion.
We then did an activity in which we saw the color ranges of the various acid-base indicators throughout the pH scale.
Today we further discussed the modern Theory of Evolution; we saw how evolution in species can be measured/defined as a change in the percentage/frequency of the various alleles in the GENE POOL of a species population. The change in allele frequency is caused by natural selection by the environment for those members of a population whose alleles give them a phenotype that is advantageous to their survival and reproduction in their environment. Thus, the surviving/reproducing members will pass on these advantageous alleles to their offspring, which will have a higher percentage of those alleles in the population.
Chem 7- we began our acid-base unit by discussing some characteristics of acids. We saw that acids are sour, react with ACTIVE metals to form aqueous salt solutions and hydrogen gas, and that acids are molecules that ionize in water to form H3O+, hydronium ion, which is often abbreviated as H+, the aqueous hydrogen ion.
Chem 8/9-we began our acid-base unit by discussing some characteristics of acids. We saw that acids are sour, react with ACTIVE metals to form aqueous salt solutions and hydrogen gas, and that acids are molecules that ionize in water to form H3O+, hydronium ion, which is often abbreviated as H+, the aqueous hydrogen ion.
We then did an activity in which we saw the color ranges of the various acid-base indicators throughout the pH scale.
# posted by C @ 12:09 PM
