Learning Issues and Lab Lessons

Term 1:
Topics- Atomic Structure, Chemical Bonding, Acid & Alkali, Period Table

Being a person who rarely excel in Science and getting merely borderline grades due to the fact that Science was one of my weaker subjects ever since primary school. Nevertheless, I struggled with the daily assignments given by Ms Nada on the respective topics, specifically on equation writing. I personally did some independent learning online by watching ‘YouTube’ videos on how to write equations. However, I was still confused and consulted my siblings and friends instead. Fortunately, they aided me along by asking me to firstly to memorise the different structures of the elements and that helped me tremendously.

Lab lessons were also beneficial. Unlike other teachers, our teacher, Ms Nada, allowed us to do the experiments on ourselves first and there was not a need to have a demonstration. From the very first lesson, we could see that she is very strict and concerned of the safety and behavior we have in the laboratory as accidents can occur very easily if we are fooling around or not alert. This term we experimented on acid and alkalis and also got a special opportunity to mix with chemicals. These lab lessons were important to me as they help me remember key concepts better such as red litmus will turn blue when in contact of acid.

Term 2:
Topics- Cycles, Sexual Reproduction

Even though the topics covered in term 2 though it seemed quite little, there were still many stuff to remember as Sexual reproduction branches out to many different topics such as menstrual cycle, STDs etc. Furthermore, acids and alkali is a very broad topic, thus we crammed all these information in order to be prepared for the tests. In my opinion the hardest were to remember the formulas for the common ionic compounds to be applied during equation writing. Unfortunately, there were no lab lessons in this term as it was mostly focused on sexual reproduction.

Term 3:
Topics- Light, Ecology

In term 3 we focused on Light and Ecology. Ecology was much simple and easier to understand when taught as food web and food chain have already been covered in primary school, so we had some basics at hand. However, the tough part for Ecology is to explain the abiotic factors and how it affects the environment. On the other hand, Light was much more challenging as we are also required to draw ray diagrams. A single mistake like drawing arrows wrongly to indicate the path/direction of light could cost you the entire question. But after much practice using the "shortcut" method, everything seemed easier.

Lab lessons this term were also enriching even though i missed some due to involvement in competitions. Unlike term 1, this term we did not work with chemicals, instead we worked with mirrors and light rays. We had the opportunity to witness how light reflects when come into contact of different shapes and mirrors. My favourite experiment was the one where we get to see total internal reflection. These experiments really aided me in memorising concepts, and to visualise to be able to draw the ray diagram.

HBL 24/5/11

In Term 2 Week 10, we had our Home-based learning. For science, we covered on Ecology, about the different relationships between organisms in an Eco-system. In short, this Home-based learning was fun, interesting and at the same time, useful.

Even though Ms Nada have briefly gone through these key concepts in class (such as predation, mutualism etc.), I am still not very good in working with these articles and identifying the respective relationships. Therefore, this Home-based learning was a great chance for me to really get hold of the basic concepts and also acts like a recap for the upcoming tests. Furthermore, I also had a better understanding and can now give examples of the types of relationships as in this activity we were told to describe the relationship of other creatures.

Personally, I actually enjoyed this home-based learning the most, as it was impactful and yet I am able to complete it in the short 1 hour period and do not have to spend quite some time like other subjects. I feel that having more of these kind of home-based learning is really good, and can really aid us in our understanding better.

Answers:

Q2. Since the Amazonian trees ants live only in the Hirtella physophora and the Amazon regions faces deforestation, deforestation will cause a decrease in the number of Hirtella physophora. This will also cause a gradual decrease in these ants as there would be more difficulty in finding places where they can inhibit and also decreasing the number of resources to build their traps, to capture their prey.

Q3(a).

Mutualism : The relationship between the ants and the plant host.

The plant provides ant with shelter and resources to construct the trap while the ants protect the plant host using their traps to protect the plant against parasitic insects and plants.

Commensalism : The relationship between the ants and the mould.

The ant makes holes in the platform and put in places pieces of sooty mould, which would quickly grow around the structure and reinforce it. On the other hand, the mould get nothing in return.

Predation : The relationship between the ants and their prey.

The ant prey on their insect and kills them. With one side benefiting, the other party suffer.

Q3.(b)

Mutualism : Clownfish and sea anemone.
The examples of mutualism include the sea anemones and hermit crab. The sea anemones give protection to the crab using its stinging cells, and it remoulds its shell to fit the crab while the hermit crab allows the sea anemones to consume the remains of its food, thus it also provides the sea anemones with food supply, which makes it a relationship beneficial to both.

Commensalism : Tree frog and plants living on trees

The tree frog uses the plants on trees for protection from the rain, and the plants are not affected at all.

Predation : Lion and deer
The lion eating the deer.

Water Shortage

Article :

There are already around 3 billion people in the world struggling to keep up with the demand for the fresh water. This number is expected to double in the next 20 years and there has been several different possible solutions for this issue such as conservation and reuse but one of the most interesting solutions definitely looks to be desalination. Why desalination? Well, lets just say that our oceans cover around 70% of our planet and therefore represent the virtually inexhaustible source of water. So why not use water desalination then and fix the water shortage problem? The main problem with desalination is that the process of removing salt from the seawater is extremely energy intensive and therefore highly expensive. There have been many different scientific studies which tried to make desalination process commercially viable but none of it has so far managed in achieving this. The currently dominating process of desalination is the so called reversal osmosis in which seawater is forced through a membrane that filters out the salt. The scientists have done several studies in which they tried to increases the membrane's water flux, and the latest researches which used carbon nanotubes have proved to be the most promising of them all. One of the most interesting recent studies comes from the University of Notre Dame. According to this study it is pointless to try to increase the membrane's water flux because the current technology is already starting to approach its efficiency limit and science should instead focus on possible gains in efficiency during the pre- and post-treatment stages of desalination. The desalination will likely play enormous role in future because this will likely remain the only available method to satisfy world's demand for water, particularly if world population continues to grow rapidly in years to come as expected.

Thoughts:

In Singapore, we have the four national taps which apart from desalination, consists of imported water, water from catchment areas and NEWater. Currently, Singapore has a desalination plant in Tuas built in 2005. Even though desalination takes up only about 10% of Singapore's water supply, in the future it is going to be a key pillar of Singapore's sustainable water supply along with NEWater which contributes 30% of consumable water. The other sources of obtaining water such as imported water are not long term solutions as agreements will expire and whether the country plans to continue the agreement with Singapore is up to the other party and this could make Singapore vulnerable even though imported water is the most efficient way and it also does not use much land space. Furthermore, despite being able to keep the cost of water treatment down, this is not a great solution too. Singapore currently has 15 reservoirs and to collect more rainwater more catchment ares have to be build and this is not very feasible as Singapore is faced with land constraints and currently, the area of the catchment areas covers up to half of Singapore's land. Therefore, i agree with the article where it claims that " The desalination will likely play enormous role in future because this will likely remain the only available method to satisfy world's demand for water, particularly if world population continues to grow rapidly in years to come as expected. " This is very likely as we a quite a rich nation, thus we can afford such technologies and the abundance of sea water available.

Reflection (Term 3)

In a blink of an eye, we have come to the end of a hectic term 3. This term was filled with competitions which resulted in missing certain lessons, thus having to catch up each time. This term's topic was on light. Practical lessons were down to the minimum considering the lack of time as method of learning was different from the previous terms. This term it was more of independence in self-study learning in which lessons were only used to clarify doubts and going through of answers in our worksheets.

Unfortunately for me, i faced difficulty trying to understand the topic depending solely on myself. I always get puzzled by the difference between convex and concave mirror, and how the image will appear on both mirrors. The drawing of the ray diagrams was also a huge hurdle for me. However, the problem was easily solved when i went to seek help from my willing friends and also my elder sister.

As physics is not a subject that could be memorised, we still hid a few scarce practical lessons to have hands-on session. This aided me a lot in understanding the laws of physics and light, both reflection and refraction.

For this term’s test, even though I got 33/40 which is an A1, I am still very much disappointed in my results as I was far below average and at least 4 marks were lost due to carelessness and sloppy drawing. To make matters worse, the test was also rather easy with only a handful that did not get A1. Now that I have basically no chance of an exemption, I will have to start on my revision for the EOYs soon, aiming for yet another A1.

Marine Biodiversity

Marine Biodiversity

Definition

- ‘Biodiversity’ is commonly defined as the variety of life in genes, species and habitats.

- For instance, the species that inhabit Singapore are different from those in Thailand, the plants and animals have different characteristics and needs, even though some of the same species can be found in all of those areas.

Importance of Biodiversity

-All living organisms are part of the web of life. Each species of vegetation and each creature has a place on the earth and plays a vital role in the circle of life.

-Biodiversity performs economic, aesthetic and recreational value

-At least 40 per cent of the world’s economy and 80 per cent of the needs of the poor are derived from biological resources. In addition, the richer the diversity of life, the greater the opportunity for medical discoveries, economic development, and adaptive responses to such new challenges as climate change.

Threats

The living inhabitants of the marine realm face four major threats:

-Overfishing (most harmful)

-Habitat damage

-Climate change

-Pollution

Overfishing

-Fishing is central to the livelihood and food security of 200 million people, especially in the developing world

-One of five people on this planet depends on fish as the primary source of protein.

-From commercial fishing, recreational fishing, illegal unregulated or unreported fishing.

-Fishing is identified as the main threat to marine ecosystems. According to a Food and Agriculture Organization (FAO) estimate, over 70% of the world’s fish species are either fully exploited or depleted.

Habit Damage

-Fishing gear commonly used to catch shrimp and bottom fish like cod and haddock, can cause long-term damage to sensitive marine ecosystems.

-E.g. A damaging method known as dredging pulls nets with a chain mesh base through soft sand or mud to catch scallops and sea urchins. These fishing gears severely destroy the ocean floor and damage the places where fish feed and breed.

Climate Change

-Human induced climate change - affects ocean temperature and levels.

-The marine creatures have to constantly adapt to the changed environment and subsequently, some eventually dying because of the drastic change.

-E.g. The increase in temperature level will cause the ice to melt, which may destroy the polar bear’s habitat

Pollution

-Most if not all pollution (air, land and many more) ultimately enters the sea.

-Marine biodiversity is thus most exposed to and critically influences the fate of pollutants in the world.

- Yet marine species are probably least resistant to toxicants. The spread of pollutants in marine food chains and therefore the quality of marine food is uncontrollable by humans.

Marvin Gaye - Mercy, Mercy Me (The Ecology)

Lyrics :

Woo ah, mercy mercy me
Ah things ain't what they used to be, no no
Where did all the blue skies go?
Poison is the wind that blows from the north and south and east
Woo mercy, mercy me, mercy father
Ah things ain't what they used to be, no no
Oil wasted on the ocean and upon our seas, fish full of mercury
Ah oh mercy, mercy me
Ah things ain't what they used to be, no no
Radiation under ground and in the sky
Animals and birds who live nearby are dying
Oh mercy, mercy me
Ah things ain't what they used to be
What about this overcrowded land
How much more abuse from man can she stand?
Oh, na na...
My sweet Lord... No
My Lord... My sweet Lord

Recently i happen to come across this song while researching stuffs on ecology. I feel that this song is really meaningful through using music to tell people about how fast the biodiversity is disappearing through pollution etc.

This is the video on youtube :

http://www.youtube.com/watch?v=U9BA6fFGMjI&feature=related

Lightning (ACE)

This is my ACE video on Lightning :

Enjoy! :)

Lightning - Jovian Tan 2A2(31)
by: Jovian Tan

Reflection (Term 2)

In term 2, we covered on Biology, focusing on the human reproductive system and ecology. These topics were quite interesting to me as it is somewhat related to us and the environment we are in. For example in ecology, we learnt about the different relation between different organisms and how it affects the entire food web if one organism is removed from the food web.

Term 2 was a disappointment. After getting an A1 in the previous test, I could only manage a mere A2 this term. I believe that my marks were lost in the MCQ section because of indecisiveness. The open-ended section was fairly good as I did not make silly mistakes.However, I feel that time management is still a huge hurdle for me. Whenever I happen to come across a challenging question, I will always attempt it and spend loads of time on it. In the case of the test, this happened and it meant that the other questions were compromised and in the end I had to rush through some of the questions which led to certain mistakes.

Perhaps the test was rather tough. I studied hard before the test but still performed unsatisfactory. I think that for next term I have to memorise what my teacher said so that I would have understood all of the necessary information before the next test and also work on time management by doing more practises. Nevertheless I still hope for an A1 though chances of exemption are very slim now.

Ecology Sabbatical Reflection

Ecology

The short but yet meaningful and purposeful week was an extreme eye-opener, I did not expect to have gain so much, to be honest I even had a mindset before the start of the course that it was going to be a drag and tedious! Being an outdoor person, I have tendency to be inclined towards sports sabbatical however this sabbatical struck my interest as we were given opportunities to go outdoors too, in this case the Underwater World, Sungei Buloh and the Raffles Museum of Biodiversity at NUS.

Therefore, I decided to opt for a different alternative this time round, partly also due to the fact that we covered Ecology in class during Term 2 hence I could really understand the topic better. Thankfully, I made the right choice!

The first lesson was mainly focused on theory and we were given a plethora of notes. Later on, for most of the time the seniors presented their wonderfully prepared PowerPoint and cleared our doubts so that we will not be lost during our field trips. One of the topics that were covered by the seniors and also in class was the many different types of organism relationships ranging from parasitism, commensalism and mutualism to predation. This topic alone was very useful and it prepares me for my term 3 test which was coincidentally also on ecology. After listening to them, I’ve gained exuberant amount of knowledge, for example the mutualism relationship between the honey guide and the honey badger. The honey guide will fly around and find a bee’s hive and lead the honey badger to it. The honey badger then smashes the hive and both animals receive a meal of honey and bee larvae, thus showing the biological interactionbetween two organisms, where each individual derives benefit.

On Thursday, we were given the privilege to explore the Underwater World, Asia’s largest tropical oceanarium. Even though I have been there a few times already, I still never fail to get amazed by the many interesting sea creatures they house! We had a whale of time there. A creature that still remains vividly in my mind is the ‘Lion’s mane jellyfish’ as it is really GARGANTUAN. Based on research online, it says that the ‘Lion’s mane jellyfish’ is the largest known species and the largest recorded specimen has tentacles approximately about 37m long! The next day was a short trip to the Raffles Museum of Biodiversity at NUS, I missed out an opportunity in primary school once therefore this was considered a valuable experience to me. The museum was filled with old artifacts that are sprayed with arsenic in order to be preserved for a long period of time. I was astonished by the ability to preserve the artifacts for such a period of time without even without wearing it. There was even a huge fish that is 3 meters long!

Through this sabbatical, I finally realized how beautiful that our nature can be and how rich it previously was. It is also disheartening to know that these creatures that we may currently have the chance to admire now might disappear in a few decades time and yet unable to do anything much as the entire world is undergoing rapid urbanization. On the other hand, I have made more friends from the pupils of outside of my consortium. This sabbatical is really amazing and awesome! Before the bidding for the next sabbatical starts, I will urge my friends to join this sabbatical and share with them the memories and experiences I had.

Man-Eater (ACE)

This is my ACE video on Man-Eaters :

Enjoy! :D

Man-eater Jovian Tan 2A2(31)
by: Jovian Tan

Assignment - STI

Hello everyone, this is a interview done by us on STI:

Done by,
Aceson Aw
Anthony Low
Hong Jin Xiang
Jovian Tan
Loh Jia Sheng

Science

After going through my term 1 Sabbatical that is related to magic, science and religion, I have some thoughts about Science. I feel that the purpose of science is to expand the human knowledge. Magic are merely illusions while religion is based on belief. On the other hand, Science is all about logic and rational when compared. Unlike thousand years ago, Science today is not the same of what is in the past, but certain principles remain the same. Science has undergone rapid development, no matter how much science develops there will still be some unanswered questions such as the origin of life which to date is unable to explained scientifically, though as time passes more questions are answered. Scientist gather evidence to create theories that explain things such as phenomenon (E.g. Newton’s Law of Motion) However on the positive side of these unanswered questions, it can drive science forward through search of new knowledge.

Perhaps, in some cases it is very difficult to determine the boundaries of science, or how much is science allowed to go, and what is considered unethical/wrong. (E.g. Clones). In this sabbatical we viewed a movie called “The Island” which mainly revolves around the clones of wealthy sponsors. In the movie, there were many problems surfaced such as the sponsors using these clones organs to save themselves for future uses. Therefore, in my opinion science, like everything else, also needs some regulations because uncontrolled science could cause many negative outcomes, doing quite the opposite of what science should realy stand for, constantly improving human well-being.

This is the trailer to the movie although it does not talk anything related to the clones. You have to watch the entire movie to know about the clones and i would say it is quite a nice movie!

The biggest star

Article : http://sciencefactsandarticles.blogspot.com/2010/07/huge-stars-in-space-biggest-one-yet.html

Recently, I came upon this interesting Science article by chance. The article is basically about astronomers discovering the most massive star of all time , R136a1 (weird name!) . For my entire life, I always thought that the Sun was the largest star, but after reading this article I realised that I was wrong all these years! R136a1 is proven to have a mass 265 times of our Sun! And when it is born it is 320 times that of the Sun's mass! From this article, I also found out that there are many stars with temperatures over 40,000 degrees - more than seven times hotter than the Sun! I can't imagine how hot it can be when I could hardly stand 35 degrees . I feel that Scientists these days are extremely good, with technology they are able to find out about planets and many other things which which we humans would have never ever thought of!

This a short 15sec clip, enjoy!

Why does ice float?

Usually, most substances are denser in their solid state than in their liquid state, which causes them to sink. However, ice frozen from water actually floats! Why is this so?

Water is the most unique substance known to man. When water freezes at 0°C, ice would be formed which is less dense than liquid. Ice floating on water is related to hydrogen bonding.

A water molecule is made up of two hydrogen atoms (H) and one oxygen atom (O). The atoms of hydrogen and oxygen are bound by sharing their electrons with one another. This is covalent bond, since oxygen atoms pull electrons more strongly than hydrogen atoms, the oxygen atom in a water molecule has a slightly negative charge and the hydrogen atoms have a slightly positive charge. Hence, neighbouring water molecules are attracted to one another through the slightly negatively charged oxygen atoms and the slightly positively charged hydrogen atoms. This interaction is called “hydrogen bonding”. Hydrogen bonding is much weaker than covalent bonding however, this type of bonding has a large total effect because there are many hydrogen bonds.

Ice has a diamond structure due to the hydrogen bonding. Water does not have such anorderly structure, but water molecules are squeezed close to one another because of the hydrogen bonding. Thus, there is more space in ice than in water. This is the reason why ice is lighter than water. Now you know why Ice can float on water!

Reflection (Term 1)

Since primary school I have always been interested in Science. Nevertheless, after going through Lower Secondary Science in Secondary 1, I realised that it is mind-cramming to remember so many facts in all three, physics chemistry and biology thus I have to really work hard in order to excel in Science.

Practicals were engaging and interesting. The numbers of hands-on activities have explained scientific concepts much better improving my understanding of the topic and make it much simpler to memorise scientific concepts. On the other hand, theory lessons were also not that bad, it was quite interesting where the teacher cleared the students’ doubts and gets us engaged using PowerPoint presentations.

My test results this term was fair but not what I aimed for. I gotten 30 out of 40 marks however, I believe that I can improve by cutting down on those careless mistakes and can study harder for the next test. Although I had obtained an A1, I am not really satisfied and I will try to work harder next term. Last but not least, I would like to take my teacher as I owe my results to her, who has successfully cleared my misconceptions and doubts before the test.