Haha, writing a post on that would probably bring some "ohhhh"s from my classmates, eh? No, no. This post is not what you think it is about.
Anyway I've just finished reading on that topic in the biology text book and I have to admit, it is much more specific than the notes given to us by the teachers. Perhaps we are not required to know so much stuff for tests, but I personally find the text book better as it allows me to understand at least 50% of what's going on in the human reproductive system and during sexual intercourse and whatever. I feel that the notes did not really provide alternative scenarios and (for me personally) it is very hard to comprehend.
Should challenge myself to reading the entire Chem, Physics and Bio textbook by the end of this year! "Ohhhhh"!
Tuesday, August 30, 2011
No lab lesson in term 3
Yup, as title suggests.
Basically we are learning biology in term 3 - ecology and sexual reproduction in humans. Biology involves living organisms, and doing biology experiments might kill those "guinea pigs" (haha, sometimes literally) involved. To avoid phone calls from SPCA or whatever, we are not doing experiments. For now, at least.
Anyway, no lab lessons mean more time for us in general - more time to do worksheets and practice papers, more time to revise by looking at the textbook, etc. - but obviously without lab lessons we are unable to actually witness the the reactions etc. stated in the textbooks or the thick stacks of notes (that also means less time to say "wow" haha). It might become a bit boring in this case, staring at the textbook trying to understand the long paragraphs of text, compared to staring at the test-tube, waiting for a reaction or observing a currently occurring one.
I hope there's lab lesson in term 4!
Basically we are learning biology in term 3 - ecology and sexual reproduction in humans. Biology involves living organisms, and doing biology experiments might kill those "guinea pigs" (haha, sometimes literally) involved. To avoid phone calls from SPCA or whatever, we are not doing experiments. For now, at least.
Anyway, no lab lessons mean more time for us in general - more time to do worksheets and practice papers, more time to revise by looking at the textbook, etc. - but obviously without lab lessons we are unable to actually witness the the reactions etc. stated in the textbooks or the thick stacks of notes (that also means less time to say "wow" haha). It might become a bit boring in this case, staring at the textbook trying to understand the long paragraphs of text, compared to staring at the test-tube, waiting for a reaction or observing a currently occurring one.
I hope there's lab lesson in term 4!
Term 3 Science Test
Last science test before the End-of-year (EOY)paper. Wasn't too pleased with my result, considering the fact that I fared below my expectations.
Didn't revise properly, really.
First, optics. Did not revise the definitions of virtual and real images. Did not really go in depth into the revision of colours. Did not memorise the types of images that can be produced by the convex lens. Honestly the questions on optics were really free marks to be given away. ALL the questions have appeared in the worksheets that I did before, and mere redoing of those would probably give me (in fact, anyone) full marks.
Now to ecology. I realise, biology has been my Achilles Heel since I flipped open that thick stack of ecology notes. And as I probably would have expected, I did not really fare well in the questions regarding ecology. Furthermore, I had not revised adequately. I merely skimmed through the definitions of habitat, ecosystem, etc. thinking that it would not come out for the test. I was wrong, of course. And that cost me a lot of marks.
I still managed to squeeze through, though, with a A1, though it really was disappointing. I felt that the class performance, too, was rather disappointing. Other than the graph showing the interrelations between the lizard, grass and grasshopper, the rest of the questions were relatively straight forward. I was expecting someone to obtain a full marks. Yet I was wrong. Again.
Didn't revise properly, really.
First, optics. Did not revise the definitions of virtual and real images. Did not really go in depth into the revision of colours. Did not memorise the types of images that can be produced by the convex lens. Honestly the questions on optics were really free marks to be given away. ALL the questions have appeared in the worksheets that I did before, and mere redoing of those would probably give me (in fact, anyone) full marks.
Now to ecology. I realise, biology has been my Achilles Heel since I flipped open that thick stack of ecology notes. And as I probably would have expected, I did not really fare well in the questions regarding ecology. Furthermore, I had not revised adequately. I merely skimmed through the definitions of habitat, ecosystem, etc. thinking that it would not come out for the test. I was wrong, of course. And that cost me a lot of marks.
I still managed to squeeze through, though, with a A1, though it really was disappointing. I felt that the class performance, too, was rather disappointing. Other than the graph showing the interrelations between the lizard, grass and grasshopper, the rest of the questions were relatively straight forward. I was expecting someone to obtain a full marks. Yet I was wrong. Again.
Monday, August 29, 2011
Anti-greenhouse effect
Heard of the greenhouse effect? Well, now there is an anti-greenhouse effect.
Basically, the greenhouse effect is something that traps sunlight and blocks infrared radiation from leaving the atmosphere, causing it to become warmer. An anti-greenhouse is the direct opposite (POLAR opposite, haha) of the greenhouse effect. It prevents sunlight from going in, and lets infrared radiation out. Polar indeed!
So far only Titan, a moon of Saturn, has been known to have the anti-greenhouse effect. "the anti-greenhouse effect on Titan reduces the surface temperature by 9 K whereas the greenhouse effect increases it by 21 K. The net effect is that the surface temperature (94 K) is 12 K warmer than the effective temperature 82 K. [i.e., the equilibrium that would be reached in the absence of any atmosphere]"(McKay et al, 1991).
Well, if the Earth has such an anti-greenhouse effect then maybe it could counter some of the greenhouse effects, like it did in Titan. As the Earth has a natural greenhouse effect (water vapour and carbon dioxide mainly) as well as a man-made one (extra carbon dioxide from factories,etc.) maybe scientists can try to create a man-made anti-greenhouse effect! Then we can save the polar ice caps!
Basically, the greenhouse effect is something that traps sunlight and blocks infrared radiation from leaving the atmosphere, causing it to become warmer. An anti-greenhouse is the direct opposite (POLAR opposite, haha) of the greenhouse effect. It prevents sunlight from going in, and lets infrared radiation out. Polar indeed!
So far only Titan, a moon of Saturn, has been known to have the anti-greenhouse effect. "the anti-greenhouse effect on Titan reduces the surface temperature by 9 K whereas the greenhouse effect increases it by 21 K. The net effect is that the surface temperature (94 K) is 12 K warmer than the effective temperature 82 K. [i.e., the equilibrium that would be reached in the absence of any atmosphere]"(McKay et al, 1991).
Well, if the Earth has such an anti-greenhouse effect then maybe it could counter some of the greenhouse effects, like it did in Titan. As the Earth has a natural greenhouse effect (water vapour and carbon dioxide mainly) as well as a man-made one (extra carbon dioxide from factories,etc.) maybe scientists can try to create a man-made anti-greenhouse effect! Then we can save the polar ice caps!
Lab lesson (II)
This term we had a series of lab lesson, conducted on a weekly basis of course. The topics for lab lesson ranged from acids and alkaline to even reflection. Of course, we had a lot of fun doing these hands-on activities.
The complex relationship between acids, bases and the other compounds or metals related to it can only be seen and understood by lab lessons and the balancing of chemical equations, coupled with some general knowledge of the atomic charge of the various compounds. In the laboratory, we amazed ourselves by creating reactions that we never expected. Bubbles bubbling out of the test tubes at a alarming speed, litmus papers changing drastically in colours, heat being emitted from the test tube, and one whole chunk of metal being vapourised in a matter of seconds shocked us, and brought us to the realisation that acids and bases are no joke and should not be trifled with.
After a few lessons full of acids and bases and the wonderful reactions that they can produce, we then went on to light. Light was a much more abstract concept - something even Einstein meddled with - and some of us could not understand it completely, resulting in a few lab lessons being substituted for normal lessons. After we had grasped the concept of reflection, real and virtual images, concave and convex mirrors and so on, we went to do a series of experiments, using a wide variety of equipments such as mirrors and a large cuboid shaped object that releases light, and also some thin black pieces of plastic shaped in such a way that only thin shafts of light can pass through. We examined reflection, virtual images, refraction and many other thing related to optics. We even got a chance to look into (haha, literally) virtual and convex mirrors, and see first-hand how the different mirrors can have an effect on the virtual image created. Of course, most of these experiments were conducted in the dark.
The complex relationship between acids, bases and the other compounds or metals related to it can only be seen and understood by lab lessons and the balancing of chemical equations, coupled with some general knowledge of the atomic charge of the various compounds. In the laboratory, we amazed ourselves by creating reactions that we never expected. Bubbles bubbling out of the test tubes at a alarming speed, litmus papers changing drastically in colours, heat being emitted from the test tube, and one whole chunk of metal being vapourised in a matter of seconds shocked us, and brought us to the realisation that acids and bases are no joke and should not be trifled with.
After a few lessons full of acids and bases and the wonderful reactions that they can produce, we then went on to light. Light was a much more abstract concept - something even Einstein meddled with - and some of us could not understand it completely, resulting in a few lab lessons being substituted for normal lessons. After we had grasped the concept of reflection, real and virtual images, concave and convex mirrors and so on, we went to do a series of experiments, using a wide variety of equipments such as mirrors and a large cuboid shaped object that releases light, and also some thin black pieces of plastic shaped in such a way that only thin shafts of light can pass through. We examined reflection, virtual images, refraction and many other thing related to optics. We even got a chance to look into (haha, literally) virtual and convex mirrors, and see first-hand how the different mirrors can have an effect on the virtual image created. Of course, most of these experiments were conducted in the dark.
Saturday, August 27, 2011
Term 2 Science Test
Managed to obtain a decent score for the Term 2 Science Test, though I feel that there is one question where I completely killed myself. I did not have ample time to finish it (and paper itself, obviously), and I think by the time I started on the ray diagrams there were only 60 ticks of the second-hand left before the end of the examination. Under such circumstances, I did not really think about how to solve the question and dived straight into drawing the path of the light ray. Furthermore, due to insufficient revision, my instinctive reaction was to draw a refracted light ray as it enters and leaves the medium, a glass semicircular object (if I remembered correctly). I certainly need to revise more for the upcoming science tests in order to prevent myself from making such mistakes again.
Sunday, March 6, 2011
Interest
I know that some of my classmates have memorised the periodic table(or at least, part of it). I also know that there is a periodic table song up on youtube that aids people in memorising it because of its catchy tunes and stuff. Obviously we don't need to memorise the periodic table for now, but it would be good to challenge yourself and try, and you will definitely need it in the future.
As for ionic and covalent bonding, some of you who have done the ACE would know that there is an exception to the general rule that metals bond ionic-ally and non-metals bond covalent-ally. Again, this might not be completely useful for now, but there is definitely need for it in the future. (I got my information from a A-level website, so perhaps these exceptions are tested for A-levels.)
However, I think for you to really be knowledgeable in Chemistry (or anything in fact), you will need to be fuelled by the passion. Learning things simply because they are needed for the future won't bring you far. Take a look at the scientists. Most of them do experiments simply because they are curious, and they have passion for experimenting, for knowing, that cannot be doused. Only with interest can you truely excel in anything.
As for ionic and covalent bonding, some of you who have done the ACE would know that there is an exception to the general rule that metals bond ionic-ally and non-metals bond covalent-ally. Again, this might not be completely useful for now, but there is definitely need for it in the future. (I got my information from a A-level website, so perhaps these exceptions are tested for A-levels.)
However, I think for you to really be knowledgeable in Chemistry (or anything in fact), you will need to be fuelled by the passion. Learning things simply because they are needed for the future won't bring you far. Take a look at the scientists. Most of them do experiments simply because they are curious, and they have passion for experimenting, for knowing, that cannot be doused. Only with interest can you truely excel in anything.
Science Test result term 1
I am rather disappointed with my results in the recent science test. Even though I got an high A1, which would definitely pull my insanely high MSG down, I still feel that I could have dome better in various aspects of the paper, particularly in the open ended section.
The first mistake I made was in the drawing of the full electronic configuration of a magnesium ion. I did not write the charge(2+) after drawing the diagram. Obviously, if I had revised properly, I would not have made such a mistake.
The second mistake was in answering the question on isotopes. I had overlooked this aspect completely in my revision and therefore was caught off guard when asked to answer this question. The answer that came of was very weak.
The third mistake was in explaining why elements C and E would form a ionic bond when together. Again, I did not revise completely for this topic and answered by saying that the electronegativity difference between the two elements was too high, causing it to be an ionic bond.
If I had revised more, especially on the ionic bonding part, and not overlook any topics that are tested on, I would obviously have gotten higher marks.
The first mistake I made was in the drawing of the full electronic configuration of a magnesium ion. I did not write the charge(2+) after drawing the diagram. Obviously, if I had revised properly, I would not have made such a mistake.
The second mistake was in answering the question on isotopes. I had overlooked this aspect completely in my revision and therefore was caught off guard when asked to answer this question. The answer that came of was very weak.
The third mistake was in explaining why elements C and E would form a ionic bond when together. Again, I did not revise completely for this topic and answered by saying that the electronegativity difference between the two elements was too high, causing it to be an ionic bond.
If I had revised more, especially on the ionic bonding part, and not overlook any topics that are tested on, I would obviously have gotten higher marks.
Lab lesson
A few weeks ago, we had a memorable lab lesson.
On one of the experiments which required the use of a bunsen burner, my friend dumped large amounts of copper into the flame. The flame then turned into a shocking green colour, probably similar to what would happen in a strike back. We all could not help but laugh, and from then on we tried pouring different types of metal, like iron and zinc, into the fire, and examined the results. Some of us even wanted to try the magnesium ribbon, but we all know that magnesium combusted in the presence of fire would form magnesium oxide, and a bright spark would also be produced.
It was later revealed that my friend only did that because he read a book on fireworks which said that dumping copper into fire would produce a green flame. In other words, only with prior knowledge did he attempt such an act. However, even if the wasn't a fire in the laboratory, there were various other implications. The technician had to attempt to pour out copper trapped in the bunsen burner, and even after a week the copper was not completely removed, and there were sometimes where parts of the fire turned green. Having witness how troublesome and potentially dangerous pouring substances to the bunsen burner can be, I would not attempt such an act.
On one of the experiments which required the use of a bunsen burner, my friend dumped large amounts of copper into the flame. The flame then turned into a shocking green colour, probably similar to what would happen in a strike back. We all could not help but laugh, and from then on we tried pouring different types of metal, like iron and zinc, into the fire, and examined the results. Some of us even wanted to try the magnesium ribbon, but we all know that magnesium combusted in the presence of fire would form magnesium oxide, and a bright spark would also be produced.
It was later revealed that my friend only did that because he read a book on fireworks which said that dumping copper into fire would produce a green flame. In other words, only with prior knowledge did he attempt such an act. However, even if the wasn't a fire in the laboratory, there were various other implications. The technician had to attempt to pour out copper trapped in the bunsen burner, and even after a week the copper was not completely removed, and there were sometimes where parts of the fire turned green. Having witness how troublesome and potentially dangerous pouring substances to the bunsen burner can be, I would not attempt such an act.
Subscribe to:
Posts (Atom)