Reflection on topics taught in term 3

In term 3, we learnt reflection of light, ecology, and the carbon cycle. I must say that the topics taught in this term are relatively easy as most of us got good grades in the term 3 tests. For reflection of light, the angle of incidence is wqual to the angle of reflection and the distance of the object from the plane mirror is same as the distance of the image form the mirror. The image is virtual as no actual light rays are captured form the screen and is upright and laterall inverted. There is the diffused reflection and the specular reflection, the type of reflection formed depends on the direction of the reflected ray, the type of surface of the reflective object and the direction of the light source. For ecology, we learnt about the different types of organisms in a food web, such as autotrophs, heterotrophs and decomposers, and the different types of relatonships of organisms, such as commensalism and exploitative relationships. There are abiotic factors that affect the ecosystem such as humidity and wind speeds. For ecology we learnt the various ways of how carbon is recycled, for example, when forests are burnt in slash and burn cultivation, large amounts of carbon dioxide is released form the destroyed plant material.

Reflection on term 2 topics

In term 2, we learnt about balancing chemical equations, acids, salts and bases, and sexual reproduction. The objective of balancing chemical equations is to balance the number of elments on each side of the equation. In acids, salts and bases, we learnt about the different reactions between acids and bases, acids and metals, the different types of indicators, and many many more. In reproduction, we learnt about the features of the reproductive systems in humans and the menstrual cycle, and STDs. The subjects learnt in this term are really challenging as the balancing of chemical equations and reproduction is hard to understand. However, I think I can do well in them if I do more practice and pay attentionin class.

Reflection on topics learnt in term 1

Now let me reflect on the topics learnt in term 1. In term one, we learnt some basic chemistry for Sec 2, which includes how covalent bonding, ionic bonding, protons, neutrons, electrons, and the periodic table. We started off with making a large periodic table using a vanguard sheet and little sheets of paper. Now let me summarise what I learnt for the term:

Elements have protons(positive charge), neutrons(neutral) and electrons(negative charge). Covalent bonding the bonding between two atoms where they share electrons to achieve the electronic configuration of a noble gas, while ionic bonding is the bonding of metallic and non metalic elements and includes the transfer of electrons to be bonded. There is also metallic bonding mentioned, but we did not learn about it.

Article on whether there is doomsday in 2012

Link to article: http://www.astroengine.com/2008/06/no-doomsday-in-2012-the-reason-why-science-will-not-win/


The author thinks that the idea of the world ending in 2012 is not real and feels angry that science is actually combined with doomsayers beliefs, such as the beliefs from the Mayan Calendar, Ancient Chinese, and the Bible. He also feels that the doomsayers are using fear to make people believe that the world will end in 2012. Personally I believe this theory because there are just so many explanations from different sources and they really convined me. I think I will just live on to see if it is true for myself.

Alfred Nobel and the dynamite

 Alfred Nobel was a Swedish industrialist, engineer, and inventor, and built bridges and buildings in Stockholm. His construction work inspired Nobel to research new methods of blasting rock. In 1860, Alfred Nobel first started experimenting with nitroglycerine,  a heavy, colorless, oily, explosive liquid.
 
  In 1863, Alfred Nobel invented the Nobel patent detonator. Itused a strong shock rather than heat combustion to ignite the explosives. The Nobel Company built the first factory to manufacture nitroglycerin and dynamite.
 
  Alfred Nobel discovered that mixing nitroglycerine with silica would turn the liquid into a malleable paste, called dynamite in 1866. One advantage of dynamite over nitroglycerin was that it could be cylinder-shaped for insertion into the drilling holes used for mining.

  In 1867, Alfred Nobel received a U.S patent for his dynamite and alsoimproved his detonator so that it could be ignited by lighting a fuse.

  In 1887, he was granted a French patent for blasting powder "ballistite".

Extras:
  When he died in 1896, Alfred Nobel left behind a nine million dollar endowment fund. The Nobel prize is awarded yearly to people whose work helps humanity. In total, Alfred Nobel held three hundred and fifty-five patents in the fields of electrochemistry, optics, biology, and physiology.

                 

2012 will not be the ned of the world-proof

For those who are worried that the world will end in like one year's time:

In 5 billion years the Sun will turn into a Red Giant

  It is said that in 5 billion years, the Sun will turn into a Red Giant. A Red Giant is a very large star of high luminosity and low surface temperature. Red giants are thought to be in a late stage of evolution when no hydrogen remains in the core to fuel nuclear fusion.

  When the Sun turns into a Red Giant, it will fuse the last of its hydrogen into helium, turn into a red giant and expand to 250 times its current size. At first, the Sun's loss of mass will loosen its gravitational pull on Earth, which will allow the planet to migrate to a wider orbit.

Some people think that the Earth might escape destruction - but survival now seems impossible, according to Peter Schröder of the University of Guanajuato in Mexico and Robert Smith of the University of Sussex in the UK. Earth's orbit will indeed widen, but Earth will also induce a "tidal bulge" on the Sun's surface, with its own gravitational pull. The bulge will lag just behind the Earth in its orbit, slowing it down enough to drag it to a fiery demise.

  There is still a little hope for humans. It is said that Earth's orbit could be tweaked by arranging the fly-by of a nearby asteroid to tug at it. This method could potentially maintain Earth's speed enough to keep it in a widening orbit, they say.

  However, people reading this post right now need not be too worried as this incident will only happen billions of years later, and we wont live to see it. Hopefully by then technology allows humans to do something to save the Earth.