3: Lesson for Term 4

Term 1 was informative, Term 2 was interesting, Term 3 was enhancing, so I hope that Term 4 would be a combination of ALL 3! That way, it would be the best Science term in the whole entire year. I am looking forward to field trips, if there might be any, and the lessons in Term 4, I will pay extra attention in preparation for the EOY coming up. I do hope I score well for it...

3: Target for Term 4

My target for Term 4 is to score a high A1 in my EOY. If I score well for the EOY, then I will get a good MSG, something that everyone wants. Of course, if I could get exempted from the EOY, it would be great, but my OP would definitely not make the mark, even if my academics could. So, I had just better set my sights on studying harder for the EOY, and talk more.

3: Test Reflection

This term's test was a failure. I scored 24/40. This is a B4. Last term, I scored 29.5/40 and got and A1. Term 1, I got 30.5/40, also an A1. This term was a big drop from the previous two terms. The section in which we were supposed to match things to their descriptions, I did not get a single one out of five right. Furthermore, I feel that even the questions for the test could have been phrased better. There was one question in which the answer was 'green', but my answer was'blue' and 'yellow. I do know that this two colours mixed becomes green, but I am still sore over that mistake. I do not know, but is it definite that anything with these two colours will mix and become green? For all we know, not all dyes mix with each other. So, I do not understand why 'blue' and 'yellow' cannot be accepted. Another question that was confusing was the last question. All of my classmates answers were in paragraph form, as well as mine. However, the model answer given was in point form! I really do not understand why the question could not have made it clearer that we could have written in point form for our answer. If the question had written that simple statement, then we could have saved a lot of time and checked our work.To me, this test was a disappointing test for me and will pull my grades down, but I still do feel that the questions could have been clearer.

3: Lesson Reflection

In Term 3, we learnt about cells, something that we learnt in Primary school. However, it was not entirely revision, as new things were taught to us, and it was like building upon our foundation. Thus, I guess that I could say the lessons this term were very good, as it helped us remember some things that we might have forgotten, and taught us fresh knowledge. But, I liked the practical lessons the most, having so much fun at the hands-on sessions.

3: What I Learned

Term 3 was pretty much just a recap on what we have learnt in Primary school. However, it was not entirely without new facts. We learnt that tissues can be divided into much more types than we were taught in Primary schools. Also, we learnt that there were 3 different types of muscles, the voluntary, smooth and cardiac muscles. Also, we learnt that in a animal cell, there were ribosomes, and also vacuoles were in them. This were all new knowledge.

3: Interesting Article

Cells

Also known as somatic stem cells, they can be found in children, as well as adults. Research into adult stem cells has been fueled by their abilities to divide or self-renew indefinitely and generate all the cell types of the organ from which they originate — potentially regenerating the entire organ from a few cells.

Unlike embryonic stem cells, the use of adult stem cells in research and therapy is not controversial because the production of adult stem cells does not require the destruction of an embryo.

Adult stem cells can be isolated from a tissue sample obtained from an adult.

They have mainly been studied in humans and model organisms such as mice and rats. The rigorous definition of a stem cell requires that it possesses two properties: Self-renewal - the ability to go through numerous cycles of cell division while maintaining the undifferentiated state. Multipotency or multidifferentiative potential - the ability to generate progeny of several distinct cell types, for example both glial cells and neurons, opposed to unipotency - restriction to a single-cell type.

Some researchers do not consider this property essential and believe that unipotent self-renewing stem cells can exist. Stem Cell Treatments Due to the ability of adult stem cells to be harvested from the patient, their therapeutic potential is the focus of much research.

Adult stem cells, similar to embryonic stem cells, have the ability to differentiate into more than one cell type, but unlike embryonic stem cells they are often restricted to certain lineages.

The ability of a stem cell of one lineage to become another lineage is called transdifferentiation.

Different types of adult stem cells are capable of transdifferentiation more than others, and for many there is no evidence of its occurrence.

Consequently, adult stem therapies require a stem cell source of the specific lineage needed and harvesting and or culturing them up to the numbers required is a challenge. Adult stem cell treatments have been used for many years to treat successfully leukemia and related bone/blood cancers through bone marrow transplants.

2: Lessons in Term 3

To me, I hope that the lessons in Term 3 would be as interesting as those in Term 2. In Term 2, I learnt things that I never knew before. The topic of elements, compounds and mixtures was totally new to me. in Term 3, we are going to be learning about cells. This topic, we have touched on in Primary school. Thus, I hope that Term 3 will give me new knowledge on cells, rather than repeat the things that we have learnt before.

2: Target for Term 3

This post would be something like a follow up from the last post that I did. My target for Term 3 would definitely be an A1, just like the other 2 terms. in Term 1, I scored 30.5. In Term 2, I scored 29.5 for the test. Thus, I hope that in Term 3, I would score 31.5 for the test. To do this, I must revise before my test, so that the knowledge I have would be fresh, so as to do my best for the test.This is my target for Term 3.

2: Test Reflection

I did a bit worse in this term's test that last term. This term, I scored 29.5 marks upon 40. Last term, I scored a 30.5 upon 40. I dropped by 1 mark, and landed just below my target - an A1! I just needed that half more mark to achieve what I wanted, but I was unable to get my mark. Thus, I had a mark just below A1. That made me very disappointed with myself. I made careless mistakes in the test, resulting in a loss of 4 marks. If I was more careful, those marks would have been mine! However, when the progress report came, I saw that I had gotten an A1. I do not know whether it was rounding up of the marks or the average from the two terms, but I made a promise to myself, that I would work harder for the next term so that I will not miss my target by such a small margin again.

2: Lesson Reflection

Following up from my previous post, my thoughts about the lessons in Term 2 is that they were very informative and interesting, as I was being taught something that I never knew before. I have gained a lot of new knowledge from this term's lessons, and it is one of the most interesting topics that I have learnt this year. I hope to have more of this kinds of lessons.

2: What I Learned

In Term 2, the topic that we learnt was on elements, compounds and mixtures. To me, I feel that this is a very interesting topic because it is something that I have never learnt before in primary school. The different elements were fascinating, studying their properties and how to apply their uses in the real world. I once thought that compounds and mixtures were one and the same, but after the lessons, I finally realized the differences.

2: Interesting Article

Elements

Discovery of two new "superheavy" elements has been announced by scientists at the U.S. Department of Energy's Lawrence Berkeley National Laboratory. Element 118 and its immediate decay product, element 116, were discovered at Berkeley Lab's 88-Inch Cyclotron by bombarding targets of lead with an intense beam of high-energy krypton ions. Although both new elements almost instantly decay into other elements, the sequence of decay events is consistent with theories that have long predicted an "island of stability" for nuclei with approximately 114 protons and 184 neutrons.

"We jumped over a sea of instability onto an island of stability that theories have been predicting since the 1970s," said nuclear physicist Victor Ninov who was first author of a paper that has been submitted to Physical Review Letters.

Said Ken Gregorich, a nuclear chemist who led the discovery team, "We were able to produce these superheavies using a reaction that, until a few months ago, we had not considered using. However, theoretician Robert Smolanczuk (a visiting Fulbright scholar from the Soltan Institute for Nuclear Studies in Poland) calculated that this reaction should have particularly favorable production rates. Our unexpected success in producing these superheavy elements opens up a whole world of possibilities using similar reactions: new elements and isotopes, tests of nuclear stability and mass models, and a new understanding of nuclear reactions for the production of heavy elements."

Gregorich and Ninov are members of Berkeley Lab's Nuclear Science Division (NSD). Walter Loveland, on sabbatical from Oregon State University, also made major contributions to this work. Other participants from the NSD included long-time leaders in the search for superheavy elements Albert Ghiorso and Darleane Hoffman, plus Diana Lee, Heino Nitsche, Wladyslaw Swiatecki, Uwe Kirbach, Carola Laue, and graduate students from the University of California at Berkeley Jeb Adams, Joshua Patin, Dawn Shaughnessy, Dan Strellis, and Philip Wilk. Hoffman and Nitsche are also professors of chemistry at UC Berkeley.

Noting that four members of the discovery team are German citizens, U.S. Secretary of Energy Bill Richardson, whose department funded this work said, "This stunning discovery which opens the door to further insights into the structure of the atomic nucleus also underscores the value of foreign visitors and what the country would lose if there were a moratorium on foreign visitors at our national labs. Scientific excellence doesn't recognize national boundaries, and we will damage our ability to perform world-class science if we cut off our laboratories from the rest of the world."

The isotope of element 118 with mass number 293 identified at Berkeley Lab contains 118 protons and 175 neutrons in its nucleus. By comparison, the heaviest element found in nature in sizeable quantities is uranium which, in its most common form, contains 92 protons and 146 neutrons. Transuranic elements in the periodic table can only be synthesized in nuclear reactors or particle accelerators. Though often short-lived, these artificial elements provide scientists with valuable insights into the structure of atomic nuclei and offer opportunities to study the chemical properties of the heaviest elements beyond uranium.

Within less than a millisecond after its creation, the element 118 nucleus decays by emitting an alpha particle, leaving behind an isotope of element 116 with mass number 289, containing 116 protons and 173 neutrons. This daughter, element 116, is also radioactive, alpha-decaying to an isotope of element 114. The chain of successive alpha decays continues until at least element 106.

"In these experiments, observation of a chain of six high-energy alpha decays within about one second unambiguously signaled the production and decay of element 118," says Gregorich. "During 11 days of experiments, three such alpha-decay chains were observed indicating production of three atoms of element 118. The decay energies and lifetimes measured for these new isotopes of elements 118, 116, 114, 112, 110, 108, and 106 provide strong support for the existence of the predicted island of stability."

Referring to these results, discovery-team member Hoffman said, "After a 30-year search, this discovery is extremely gratifying. I only wish Glenn Seaborg had been alive to see these results." Seaborg, the recently deceased Nobel laureate chemist and co-discoverer of plutonium and nine other transuranic elements, was one of the earliest and most outspoken advocates of experiments to reach the predicted island of stability.

Elements 118 and 116 were discovered by accelerating a beam of krypton-86 ions to an energy of 449 million electron volts and directing the beam into targets of lead-208. This yielded heavy compound nuclei at low excitation energies.

During the last several years, low excitation energy reactions failed to take scientists beyond element 112, and it was assumed that production rates for heavier elements were too small to extend the periodic table further using this approach. However, the recent calculations of Smolanczuk indicating increased production rates for the Kr-86 + Pb-208 reaction prompted the experimental search for element 118 at Berkeley Lab.

The key to the success of this experiment was the newly constructed Berkeley Gas-filled Separator (BGS). Said Gregorich, "The innovative BGS design has resulted in a separator with unsurpassed efficiency and background suppression which allows us to investigate nuclear reactions with production rates smaller than one atom per week. For these experiments, the strong magnetic fields in the BGS focused the element 118 ions and separated them from all of the interfering reaction products which were produced in much larger quantities."

Another important factor for the experiment's success was the unique ability of the 88-Inch Cyclotron to accelerate neutron-rich isotopes such as krypton-86 to high-energy and high-intensity beams with an average current of approximately 2 trillion ions per second.

"The 88-inch Cyclotron is the only accelerator in the United States at this time that can provide krypton beams at the intensities that this experiment demanded," said Claude Lyneis, the NSD physicist who heads the accelerator facility for Berkeley Lab.

In operation since 1961, the 88-inch Cyclotron has been upgraded with the addition of a high-performance ion sources and can now accelerate beams of ions as light as hydrogen or as heavy as uranium. The 88-Inch Cyclotron is a national user facility serving researchers from around the world for basic and applied studies.

Said I-Yang Lee, scientific director at the 88-Inch Cyclotron, "From the discovery of these two new superheavy elements, it is now clear that the island of stability can be reached. Additionally, similar reactions can be used to produce other elements and isotopes, providing a rich new region for the study of nuclear and even chemical properties."

Berkeley Lab is a U.S. Department of Energy national laboratory located in Berkeley, California. It conducts unclassified scientific research and is managed by the University of California.

1: Lessons in Term 2

I wish to learn the difference between the three different sciences in secondary school, chemistry, biology and physics. I have a rough idea about the meaning of chemistry and biology, but I have no idea what is physics. I also want to know why it is that the three sciences must be studied separately in upper secondary, and not as one. Also, as mentioned in the intro, I really hope to learn more about science and expand my knowledge about the world around me. In other words, I want to learn more about science. I really hope to achieve that goal I have set for myself.

1: Target for Term 2

The most obvious answer would be that I would like to see my science grades go up from a ‘just nice’ A1 to a medium A1, and hopefully a high A1. That is the simplest answer and one that everyone can give. However, we do not study just to get high marks. Of course everyone wants high marks, but that pales in comparison to the fact that we study so that we can build up our knowledge and make it easier to find a job in the later part of our lives. So, the latter will be my ultimate goal, but I will just settle for the first one at the moment.

1: Test Reflection

The term 1 test result were not very good, to say the least. I had expected higher marks for the test, and not a 'just nice' A1 mark for it, but who do I have to blame but myself? I made a lot of careless mistakes in the test, and some of the answers I knew, but just could not recall it. This little things pulled down my marks for the test by a lot. If there was another mistake, there goes my A1. I promised myself that I would do better in my next test, and study harder for it.

1: Lesson Reflection

I feel that on a whole, the lessons of term 1 were ok, but the lessons that I liked most were the practical sessions in the science laboratory. I tried a lot of experiments that I had never done before, and repeated a few experiments that have been completed in primary 5 or primary 6, but I just took the repeated experiments as revision. I learnt that there are a lot of different ways that one can learn new things, not just through books and lectures, but through hands-on experiments too. This way of learning might be better for some people.

1: What I Learned

The topic we touched on most in term 1 was the Bunsen burner and the different types of flames that it produces, and also the different apparatus that are used in science experiments in the science laboratory. The Bunsen burner can produce two types of flames, the luminous and the non-luminous flame. The luminous flame occurs when the air hole is closed, so that there is very little air, while the non-luminous flame occurs when the air hole is partially open. There is something called a strike back, when too much air is let into the Bunsen burner at once. The apparatus in the science laboratory were explained to us about their functions, and we were expected to know how to draw them.

1: Interesting Article

Bunsen Burner

The device in use today safely burns a continuous stream of a flammable gas such as natural gas (which is principally methane) or a liquefied petroleum gas such as propane, butane, or a mixture of both.

The hose barb is connected to a gas nozzle on the lab bench with rubber tubing. Most lab benches are equipped with multiple gas nozzles connected to a central gas source, as well as vacuum, nitrogen, and steam nozzles. The gas then flows up through the base through a small hole at the bottom of the barrel and is directed upward. There are open slots in the side of the tube bottom to admit air into the stream via the Venturi effect, and the gas burns at the top of the tube once ignited by a flame or spark. The most common methods of lighting the burner are using a match or a spark lighter.

The amount of air (or rather oxygen) mixed with the gas stream affects the completeness of the combustion reaction. Less air yields an incomplete and thus cooler reaction, while a gas stream well mixed with air provides oxygen in an equimolar amount and thus a complete and hotter reaction. The air flow can be controlled by opening or closing the slot openings at the base of the barrel, similar in function to the choke in a car's carburetor.

If the collar at the bottom of the tube is adjusted so more air can mix with the gas before combustion, the flame will burn hotter, appearing blue as a result. If the holes are closed, the gas will only mix with ambient air at the point of combustion, that is, only after it has exited the tube at the top. This reduced mixing produces an incomplete reaction, producing a cooler but brighter yellow which is often called the "safety flame" or "luminous flame". The yellow flame is luminous due to small soot particles in the flame which are heated to incandescence. The yellow flame is considered "dirty" because it leaves a layer of carbon on whatever it is heating. When the burner is regulated to produce a hot, blue flame it can be nearly invisible against some backgrounds. The hottest part of the flame is the tip of the inner flame, while the coolest is the whole inner flame. Increasing the amount of fuel gas flow through the tube by opening the needle valve will of course increase the size of the flame. However, unless the airflow is adjusted as well, the flame temperature will decrease because an increased amount of gas is now mixed with the same amount of air, starving the flame of oxygen. The blue flame in a Bunsen burner is hotter than the yellow flame.

The burner will often be placed on a suitable heatproof mat to protect the lab bench.

Self Introduction

My name is Tan Chuan Xin and I am 13 years old. I am currently studying in Hwa Chong Institution, and my class is 1P4. I really hope to learn more about science and expand my knowledge about the world around me, and know how things work during my year of studying science in secondary 1. I do feel that science is a very interesting subject, and one that knowledge is constantly being created in, so I will be a bit more interested in science than all other subjects. I do hope to do well for my science results in the end of year exam, and all the other tests before it.