Sigh********
Again, I got A1 for science. Again, a low A1! Again, happy, yet dissapointed.
I began my revision way before the test this time. However, i still fell on the topic reflection. Perhaps, i was too confident that I will score well for the test. Perhaps, if I had spend more time revising, perhaps.............
No matter what I say now, I cannot change the history. I have made my decision to start studying for next term NOW.
Hope that this term's effort can make next term's test a breeze.........
Saturday, May 28, 2011
Thursday, May 5, 2011
term 1 reflection
Despite optaining an A1, I realised that it was not good enough.
I still need to improve on my chemical bonding and equation writing as my understanding of these topics are not thorough.
Indeed, I did a lot of revision before the test. However, I only started my revision 2 days before the test. This perhaps is the reason why I feel that I am not working hard enough.
However, compared to last year's result I have improved quite a bit as I scored a B4 for science last year. B4 to A1, it took me very long to achieve this. (I never had an A1 for science last year)
I am not satisfied with my results yet. Trying to work harder for next term's test!
I still need to improve on my chemical bonding and equation writing as my understanding of these topics are not thorough.
Indeed, I did a lot of revision before the test. However, I only started my revision 2 days before the test. This perhaps is the reason why I feel that I am not working hard enough.
However, compared to last year's result I have improved quite a bit as I scored a B4 for science last year. B4 to A1, it took me very long to achieve this. (I never had an A1 for science last year)
I am not satisfied with my results yet. Trying to work harder for next term's test!
Monday, May 2, 2011
type 1-A supernova
Everything around us are made from supernovae. From our head to our toes, from the land to the sea. All these come from the supernovae.
A single supernova can outshine the entire galaxy , releasing trillion times of the energy released by our Sun. They are so powerful that if one explode in a few light years away, earth would be toast.
Most stars are basically giant nuclear reactors. The reaction fuses hydrogen atoms together, producing helium and energy. When hydrogen runs out, stars keep burning by fusing helium into carbon, then carbon into oxygen. In a normal star, there is a balance between gravity pulling in and pressure pushing out. However, once the star stops generating energy, the pressure goes away and gravity wins. Then the gravity will begin to crush the centre of the star. The star's outer layer will expand rapidly while the the gravity will crush its core to just a millionth of its original size. It is now a dense spot of oxygen and carbon called white dwarf. The gas of the star will disperse but the tiny white dwarf will remain.
As most of the stars come in pairs, when one dies, its white dwarf starts stealing material from the other, slowly sucking the hydrogen and helium from the other star. As it does so, it gets heavier and denser. Inside, carbon and oxygen atoms are about to fuse together. This star is slowly turning into a type 1-A supernova. Eventually the white dwarf sucks so much energy from its companion that it goes into nuclear overload. The oxygen and carbon will fuse and turn into iron and at this oint in time, the white dwarf explodes. The element iron found in our blood and other things on earth mostly comes from this type 1-A supernova.
A single supernova can outshine the entire galaxy , releasing trillion times of the energy released by our Sun. They are so powerful that if one explode in a few light years away, earth would be toast.
Most stars are basically giant nuclear reactors. The reaction fuses hydrogen atoms together, producing helium and energy. When hydrogen runs out, stars keep burning by fusing helium into carbon, then carbon into oxygen. In a normal star, there is a balance between gravity pulling in and pressure pushing out. However, once the star stops generating energy, the pressure goes away and gravity wins. Then the gravity will begin to crush the centre of the star. The star's outer layer will expand rapidly while the the gravity will crush its core to just a millionth of its original size. It is now a dense spot of oxygen and carbon called white dwarf. The gas of the star will disperse but the tiny white dwarf will remain.
As most of the stars come in pairs, when one dies, its white dwarf starts stealing material from the other, slowly sucking the hydrogen and helium from the other star. As it does so, it gets heavier and denser. Inside, carbon and oxygen atoms are about to fuse together. This star is slowly turning into a type 1-A supernova. Eventually the white dwarf sucks so much energy from its companion that it goes into nuclear overload. The oxygen and carbon will fuse and turn into iron and at this oint in time, the white dwarf explodes. The element iron found in our blood and other things on earth mostly comes from this type 1-A supernova.
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