I chose astatine as my halogen because I had never heard of it before. It's name comes from the Greek word "astatos," meaning "unstable." This highly radioactive halogen was synthesized in 1940 at U.C. by bombarding bismuth with alpha particles. The total amount of astatine present in the earth's crust is less than one ounce. According to the article I read at www.periodic.lanl.gov/elements/85, the "time of flight" mass spectrometer has been used to confirm that, chemically, astatine behaves much like iodine and probably accumulates in the thyroid gland. It differs from iodine in that it is more metallic.
I chose krypton as my inert gas because I wanted to see if I could figure out the secret of Superman's heroic feats. While I continue to investigate the secrets of Superman, I will share with you what I learned about krypton.
The name "krypton" comes from the Greek word "kryptos" meaning "hidden." Krypton was discovered on May 30, 1898 by Sir William Ramsay, a Scottish chemist, and Morris M. Travers, an English chemist, while they were studying liquified air. Small amounts of liquid krypton remained after more volatile components had boiled away. Krypton comprises 0.0001% of the earth's atmosphere.
Krypton is used in some types of flashes used in high speed photography. It is combined with argon in some types of fluorescent light bulbs and with other gases to make what we would refer to as "neon" signs.
I selected tellurium as my semiconductor because its name is similar to Telluride, which makes me think of skiing, and skiing is something that we might do during the winter trimester, if we were not in class.
Tellurium is silvery-white and, in its pure form, has a metallic lustre. It is brittle and easily crushed into a powder form. Tellurium ores exist, but tellurium is a byproduct of copper refining.
Tellurium is a "p-type" semiconductor. Its conductivity increases slightly when it is exposed to light. Besides its use as a semiconduct, tellurium is added to lead to prevent corrosion, and it is also used in ceramics and for tinting glass.
Interestingly, humans exposed to miniscule amount of tellurium develop "tellurium breath," which smells like garlic.
Monday, April 7, 2008
Wednesday, April 2, 2008
WEEK 11/12
How Cells Divide: Mitosis v. Meiosis
In all honestly, cell division is one of the few biology topics that does not fascinate me from a learner's perspective. Maybe I was traumatized by the memorization required on the topic by my junior high and high school teachers. The NOVA slides were great for visualization purposes, and I liked the breakdown of explanatory text with each slide. I just wish they could have used flourescent/microscopic pictures of the process like those that appear on the Wikipedia links.
Connections Between TCM and Cell Biology
Hmm. I don't have enough TCM study behind me to feel enlightened about these connections. TCM seems to focus on macrocellular levels - interrelationships between organs and systems within the body - not on the intricacies of cellular life cycles.
In all honestly, cell division is one of the few biology topics that does not fascinate me from a learner's perspective. Maybe I was traumatized by the memorization required on the topic by my junior high and high school teachers. The NOVA slides were great for visualization purposes, and I liked the breakdown of explanatory text with each slide. I just wish they could have used flourescent/microscopic pictures of the process like those that appear on the Wikipedia links.
Connections Between TCM and Cell Biology
Hmm. I don't have enough TCM study behind me to feel enlightened about these connections. TCM seems to focus on macrocellular levels - interrelationships between organs and systems within the body - not on the intricacies of cellular life cycles.
Wednesday, March 19, 2008
Week 10 addendum
Hmm. I wish that I had been in class last week to refresh my recollection of what constitutes a "species" (family, genus, species . . .). I know that my environment is teeming with microscopic organisms, but I don't remember if they are "species." Anyway, there are humans in my home. And, thanks to my husband, there are three living plants in my home, each of a different variety. We have a small backyard that is visited every night by raccoons and every morning by at least three varieties of birds. The soil in our garden contains some earthworms. Ants and spiders roam around outside. A mystery creature visits the garden and eats all of the vegetables and herbs, except the parsley.
Monday, March 17, 2008
WEEK 10
Cell Structures
I liked the depiction of the virus in a "Space Invader" style, different and threatening to the other cells. I also enjoyed reading about bacteria. The protective capsule that some of them have was news to me, and it helped me understand why some strains of bacteria seem to very resistant to the body's defenses.
The interactive cell was "cute" but not very informative; I preferred the long text and diagrams in the other sites.
Spike's Photos
It struck me that these little water organisms look like things I see up here on the land. The phantom larva reminded me of Jack in Nightmare Before Christmas - big head and eyes and wispy little body. The diatoms reminded me of my great grandmother's button collection. There were beautiful little bubble creatures. The daphnia looks like a graceful, multi-armed symphony conductor. The water flea looks like the cartoon version of a reindeer head. The first image looks just like a fish . . . clearly at home in his water habitat.
The Fieldtrip
The fieldtrip was fantastic . . . although, I would not have been disappointed if I had missed the pit of stinky garbage on which the birds were feasting. The sculpture garden was terrific. It's a marvelous contrast to the junk on the property, and I was happy to learn that talented gardeners can resurrect plants that have been given up for dead. I was surprised to learn that plastic is not as recyclable as glass -- it can never be completely reduced to its original form and reconstructed . . . yet another change for me to make in my consumer choices. Of course, my daughter and I enjoyed the art, particularly the interactive pieces. I found the lecture engaging and interesting, although my daughter did not . . . perhaps it's just the superior knowledge of a younger generation.
I liked the depiction of the virus in a "Space Invader" style, different and threatening to the other cells. I also enjoyed reading about bacteria. The protective capsule that some of them have was news to me, and it helped me understand why some strains of bacteria seem to very resistant to the body's defenses.
The interactive cell was "cute" but not very informative; I preferred the long text and diagrams in the other sites.
Spike's Photos
It struck me that these little water organisms look like things I see up here on the land. The phantom larva reminded me of Jack in Nightmare Before Christmas - big head and eyes and wispy little body. The diatoms reminded me of my great grandmother's button collection. There were beautiful little bubble creatures. The daphnia looks like a graceful, multi-armed symphony conductor. The water flea looks like the cartoon version of a reindeer head. The first image looks just like a fish . . . clearly at home in his water habitat.
The Fieldtrip
The fieldtrip was fantastic . . . although, I would not have been disappointed if I had missed the pit of stinky garbage on which the birds were feasting. The sculpture garden was terrific. It's a marvelous contrast to the junk on the property, and I was happy to learn that talented gardeners can resurrect plants that have been given up for dead. I was surprised to learn that plastic is not as recyclable as glass -- it can never be completely reduced to its original form and reconstructed . . . yet another change for me to make in my consumer choices. Of course, my daughter and I enjoyed the art, particularly the interactive pieces. I found the lecture engaging and interesting, although my daughter did not . . . perhaps it's just the superior knowledge of a younger generation.
Tuesday, February 12, 2008
Alkali Earth Metal of the Week: Barium
For my own reference, alkali earth metals make up the second family of the perodic table. Alkali earth metals usually give up two electrons in a chemical compound. They are too reactive to be found in their pure state in nature, and they are denser and not as soft as alkali metals.
The following site had lots of interesting trivia about alkali earth metals, and I got carried away reading about all of the earth metals, instead of focusing on barium, my alkali earth metal of the week: http://www.theodoregray.com/PeriodicTable/Elements/056/index.s7.html#sample3
Barium caught my attention because I remember that in connection with radiation cancer treatments in the 1970s, my great grandmother had to have barium enemas. I thought that I remembered her drinking a barium concoction that she found revolting, but after doing some research, I'm not so sure that my recollection of 30 years ago is accurate. I did learn that a barium solution is injected into the colon for a lower gastrointestinal x-rays to "illuminate" the colon and reveal polyps or other abnormalities on the x-ray image.
I came across an interesting study in which the author suggested that there is a link between higher concentrations of barium in the the soil and increased incidence of multiple sclerosis and other deriorative neurlogical diseases. The article is at http://www.wnho.net/BariumPoisoningStudy.pdf.
The following site had lots of interesting trivia about alkali earth metals, and I got carried away reading about all of the earth metals, instead of focusing on barium, my alkali earth metal of the week: http://www.theodoregray.com/PeriodicTable/Elements/056/index.s7.html#sample3
Barium caught my attention because I remember that in connection with radiation cancer treatments in the 1970s, my great grandmother had to have barium enemas. I thought that I remembered her drinking a barium concoction that she found revolting, but after doing some research, I'm not so sure that my recollection of 30 years ago is accurate. I did learn that a barium solution is injected into the colon for a lower gastrointestinal x-rays to "illuminate" the colon and reveal polyps or other abnormalities on the x-ray image.
I came across an interesting study in which the author suggested that there is a link between higher concentrations of barium in the the soil and increased incidence of multiple sclerosis and other deriorative neurlogical diseases. The article is at http://www.wnho.net/BariumPoisoningStudy.pdf.
Wednesday, February 6, 2008
Week 5 Assignments
What Colors Are in My Kitchen?
Red: lots of tomato sauce, spaghetti sauce, and canned tomatoes of all varieties, steak, ruby red grapefruit, raspberry jam, frozen rasperries, fuji apples, salsa, chicken, pork
Green: Romaine lettuce, celery, pickles, jalapenos, frozen peas, broccoli, cabbage
Yellow: Bananas, a lemon (does mustard count?)
Brown: Blue Moon and Amstel Light beer, steelcut oats, brown rice, bulgur, lentils, whole wheat pasta, peanut butter, honey, brown sugar, almonds
Purple: Red Wine, black beans, dried anti-oxidant fruit blend (cherries, plums, etc.), raisins
White: Garlic, onions, milk, coconut milk
Orange: mandarin orange-flavored chicken :) [a clear deficit in the orange category]
Beige: Lots of dairy products: nonfat milk, parmesan cheese, cheddar cheese, cream cheese, American cheese, processed cheese spreads; lots of white bread stuff (i.e., sandwich bread, hot dog buns, bagels); white rice, russet potatoes, ramen noodles, Kelloggs' frozen waffles, Cinnamon Toast Crunch cereal, Fruity Pebbles cereal, turkey jerky, Sun Chips, Doritos, Veggie Chips (carrot, tomato and spinach), Cheetos
Red: lots of tomato sauce, spaghetti sauce, and canned tomatoes of all varieties, steak, ruby red grapefruit, raspberry jam, frozen rasperries, fuji apples, salsa, chicken, pork
Green: Romaine lettuce, celery, pickles, jalapenos, frozen peas, broccoli, cabbage
Yellow: Bananas, a lemon (does mustard count?)
Brown: Blue Moon and Amstel Light beer, steelcut oats, brown rice, bulgur, lentils, whole wheat pasta, peanut butter, honey, brown sugar, almonds
Purple: Red Wine, black beans, dried anti-oxidant fruit blend (cherries, plums, etc.), raisins
White: Garlic, onions, milk, coconut milk
Orange: mandarin orange-flavored chicken :) [a clear deficit in the orange category]
Beige: Lots of dairy products: nonfat milk, parmesan cheese, cheddar cheese, cream cheese, American cheese, processed cheese spreads; lots of white bread stuff (i.e., sandwich bread, hot dog buns, bagels); white rice, russet potatoes, ramen noodles, Kelloggs' frozen waffles, Cinnamon Toast Crunch cereal, Fruity Pebbles cereal, turkey jerky, Sun Chips, Doritos, Veggie Chips (carrot, tomato and spinach), Cheetos
Links to websites:
After reviewing the websites this week, the subject that intrigues me most is bioluminescence. I love to scuba dive and enjoy night diving because of the marine version of fireflies. There are all sorts of bioluminescent creatures in the ocean. I went on a night dive in Kona last June, and we created a zone of light which attracted plankton that manta rays like to eat. I need to go back and read about all of the types of luminescence to see if something other than bioluminescence was at play.
Catalyst of the Week - Vanadium
I have to admit that I'm a little lost on the catalysts. In my research, I kept finding transition elements as catalysts. I did not find references to other elements as catalysts. What am I missing?
Vanadium oxide is the transition element-compound [what is the difference between and element and an "element-compound?] that catalyses sulphur dioxide to sulphur trioxide in the contact process for the manufacture of sulphuric acid.
I found many references to "contact process" in my research. What is the "contact process" and how does it relate to catalysts?
Vanadium oxide is the transition element-compound [what is the difference between and element and an "element-compound?] that catalyses sulphur dioxide to sulphur trioxide in the contact process for the manufacture of sulphuric acid.
I found many references to "contact process" in my research. What is the "contact process" and how does it relate to catalysts?
Monday, January 28, 2008
Molecular Modeling
I reviewed most of this week's links, struggling to find one that made any sense at all to me. Some moved too fast; two dimensions didn't do much to help me; one site depicted many different tri-colored blobs. But, I liked the water model. The depiction of the hydrogen molecules in motion, bonding and breaking (at a pace that I could actually watch), reminded me of irregular waves caused by raindrops splashing in a puddle. I could connect the notion of the weak hydrogen bonds breaking and reforming with an image of water droplets splashing apart in a puddle and then rebonding (becoming part of the puddle).
Sunday, January 27, 2008
Carbon: A picture is worth a thousand words
Go to the link below to see the structure of carbon atoms in graphite, diamonds, and fullerenes.
http://www.edinformatics.com/interactive_molecules/carbon_jmol.htm
http://www.edinformatics.com/interactive_molecules/carbon_jmol.htm
Rhenium in Transition
Did you know that rhenium (pronounced ri-neum) was the next-to-last naturally occurring element to be discovered?
Its name derives from the Latin term rhemus meaning Rhine. Those who know their world geography will deduce from its name that it was discovered in . . . Germany, in the year 1925.
Rhenium is clingy and reclusive. It is not found free; rather, it is detected in ores, like platinum and porphyry copper, and minerals, like columbite. It's favorite companion is molybdenum. Rhenium is recovered as a byproduct from roasting molybdenum concentrates.
Recovering rhenium is an expensive process, which lends to rhenium's distinction of making the list of the top 10 most expensive transition metals. During 2006, average rhenium metal price was a whopping $1,170 per kilogram, but it rose as high as $5,000 per kilogram when Kazakhstan refused to supply it to the U.S. for several months!
Rhenium is a component of platinum-rhenium catalysts that are used primarily in producing lead-free, high-octane gasoline and in high-temperature superalloys used for jet engine components.
The largest producer of rhenium has always been Chile. Kazakhstan has become the second largest producer. The United States relies heavily on rhenium imports, as it produces rhenium from only six mines in the U.S.: Two in Arizona and one each in Montana, Nevada, New Mexico and Utah.
Its name derives from the Latin term rhemus meaning Rhine. Those who know their world geography will deduce from its name that it was discovered in . . . Germany, in the year 1925.
Rhenium is clingy and reclusive. It is not found free; rather, it is detected in ores, like platinum and porphyry copper, and minerals, like columbite. It's favorite companion is molybdenum. Rhenium is recovered as a byproduct from roasting molybdenum concentrates.
Recovering rhenium is an expensive process, which lends to rhenium's distinction of making the list of the top 10 most expensive transition metals. During 2006, average rhenium metal price was a whopping $1,170 per kilogram, but it rose as high as $5,000 per kilogram when Kazakhstan refused to supply it to the U.S. for several months!
Rhenium is a component of platinum-rhenium catalysts that are used primarily in producing lead-free, high-octane gasoline and in high-temperature superalloys used for jet engine components.
The largest producer of rhenium has always been Chile. Kazakhstan has become the second largest producer. The United States relies heavily on rhenium imports, as it produces rhenium from only six mines in the U.S.: Two in Arizona and one each in Montana, Nevada, New Mexico and Utah.
Monday, January 14, 2008
Cultural Influence of Chemistry: Natural Disasters
How much do we really understand the effects of natural disasters and global warming?
Through experience, the human race understands the present effects of natural disasters and global warming. I believe that we do not grasp the scale of the future effects of natual disasters and global warming. We seek to understand the causes during and after we have experienced the effect, which captures the media spotlight. After we have addressed the immediate effect, we tend to lose our interest in preventing the next disaster until it is upon us once again.
I remember taking an Environmental Issues class at Berkeley in 1988. Global warming was discussed at length. Once I left that classroom, I heard very little about global warming until Al Gore's movie gave rise to heated debate between groups of my friends.
The geologists, chemists, and biologists who are among my friends have expressed no uncertainty about the effects of global warming and the need to take action. On the other hand, the majority of my friends who lack science backgrounds have been skeptical about the Al Gore movie. In fact, some of these people expressed outrage when their children came home from school talking about what they had learned about global warming.
I remember my parents reacting with the same skepticism in the late 197o's and early 1980's when I came home from school convinced that we needed to rely on alternative energy sources, particularly solar power, instead of petroleum. The economic incentives for using alternative energy all but disappeared during the Reagan era and have not re-emerged yet in any meaningful way.
These experiences have led me to conclude that there is no shortage of understanding in the scientific community about global warming; however, many of us hear what we want to hear, and we don't ask questions when we suspect that we won't like the answers. Our difficulties are not in failure to understand, but rather, in our failure to accept and act.
Through experience, the human race understands the present effects of natural disasters and global warming. I believe that we do not grasp the scale of the future effects of natual disasters and global warming. We seek to understand the causes during and after we have experienced the effect, which captures the media spotlight. After we have addressed the immediate effect, we tend to lose our interest in preventing the next disaster until it is upon us once again.
I remember taking an Environmental Issues class at Berkeley in 1988. Global warming was discussed at length. Once I left that classroom, I heard very little about global warming until Al Gore's movie gave rise to heated debate between groups of my friends.
The geologists, chemists, and biologists who are among my friends have expressed no uncertainty about the effects of global warming and the need to take action. On the other hand, the majority of my friends who lack science backgrounds have been skeptical about the Al Gore movie. In fact, some of these people expressed outrage when their children came home from school talking about what they had learned about global warming.
I remember my parents reacting with the same skepticism in the late 197o's and early 1980's when I came home from school convinced that we needed to rely on alternative energy sources, particularly solar power, instead of petroleum. The economic incentives for using alternative energy all but disappeared during the Reagan era and have not re-emerged yet in any meaningful way.
These experiences have led me to conclude that there is no shortage of understanding in the scientific community about global warming; however, many of us hear what we want to hear, and we don't ask questions when we suspect that we won't like the answers. Our difficulties are not in failure to understand, but rather, in our failure to accept and act.
Quiz results
My answers to Richard Banks' quiz:
1. Classify the following as either a chemical or physical change.
Burning wood : physical
Crushing a rock : physical
Dissolving sugar in water : physical
The rusting of iron: chemical
2. Classify the following as to whether or not they are pure substances or mixtures.
milk: mixture
table salt : mixture
sugar : pure
steel : mixture
3. A cup of black coffee is considered to be __?__ and a/an __?__ substance.
(a) homogeneous…..pure
(b) homogeneous…..impure
(c) non-homogeneous…pure
(d) non-homogeneous…impure
I chose non-homogenous impure first. Apparently, that is not necessarily correct, but I can't say that I understand why. Perhaps I assumed a cup of brewed coffee and the question referred to a cup of coffee beans? Is that the difference?
4. The boiling of water is considered to be a __?__ change and the temperature at which water boils is considered to be a __?__ property. Answer: (d)
(a) chemical…..chemical
(b) chemical…..physical
(c) physical…..chemical
(d) physical…..physical
1. Classify the following as either a chemical or physical change.
Burning wood : physical
Crushing a rock : physical
Dissolving sugar in water : physical
The rusting of iron: chemical
2. Classify the following as to whether or not they are pure substances or mixtures.
milk: mixture
table salt : mixture
sugar : pure
steel : mixture
3. A cup of black coffee is considered to be __?__ and a/an __?__ substance.
(a) homogeneous…..pure
(b) homogeneous…..impure
(c) non-homogeneous…pure
(d) non-homogeneous…impure
I chose non-homogenous impure first. Apparently, that is not necessarily correct, but I can't say that I understand why. Perhaps I assumed a cup of brewed coffee and the question referred to a cup of coffee beans? Is that the difference?
4. The boiling of water is considered to be a __?__ change and the temperature at which water boils is considered to be a __?__ property. Answer: (d)
(a) chemical…..chemical
(b) chemical…..physical
(c) physical…..chemical
(d) physical…..physical
Periodic Table Links
I visited each of the Periodic Table links identified on our class blog.
The "chemical elements" link humbled me: If this is a reference for elementary, middle school, and high school students, how did I ever make it through graduate school?
The "interactive" link was helpful. It's convenient to have many different (and colorful) ways to look at the information that is captured on the periodic tables.
The "spiral" link looked trippy and seemed to have some logic to it. Unfortunately, I have no idea what the logic is.
My favorite, by far, was the "memory" link by John Pratt. If I had to memorize all of the elements on the periodic table, I would use this tool. The pictures are easily identifiable, and the explanations of how the elements are linked to the pictures are easy to recall.
The "quiz" link was of no help. I scored 50% on the quiz but learned nothing about electron/neutron/ion counts and how they relate to atomic weight.
The "game" link: Love it!!! I could play this game forever with my kids, and eventually we would all learn the elements of the periodic table. I felt very competent when I received a 10/10 score on a couple of the quizzes and was able to e-mail those test results to my husband!! I did notice while playing the naming game that I was able to receive an artificially inflated score because the quiz asked me three times to name "H". Because I was able to type "hydrogen" correctly all three times, I earned 3/3 points. I probably would have received a lower overall score, if I had to name three different elements instead.
The "rejected" link: What can I say? I like to side with the underdogs, and agree that grenadine belongs on the periodic table.
The "chemical elements" link humbled me: If this is a reference for elementary, middle school, and high school students, how did I ever make it through graduate school?
The "interactive" link was helpful. It's convenient to have many different (and colorful) ways to look at the information that is captured on the periodic tables.
The "spiral" link looked trippy and seemed to have some logic to it. Unfortunately, I have no idea what the logic is.
My favorite, by far, was the "memory" link by John Pratt. If I had to memorize all of the elements on the periodic table, I would use this tool. The pictures are easily identifiable, and the explanations of how the elements are linked to the pictures are easy to recall.
The "quiz" link was of no help. I scored 50% on the quiz but learned nothing about electron/neutron/ion counts and how they relate to atomic weight.
The "game" link: Love it!!! I could play this game forever with my kids, and eventually we would all learn the elements of the periodic table. I felt very competent when I received a 10/10 score on a couple of the quizzes and was able to e-mail those test results to my husband!! I did notice while playing the naming game that I was able to receive an artificially inflated score because the quiz asked me three times to name "H". Because I was able to type "hydrogen" correctly all three times, I earned 3/3 points. I probably would have received a lower overall score, if I had to name three different elements instead.
The "rejected" link: What can I say? I like to side with the underdogs, and agree that grenadine belongs on the periodic table.
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