Tuesday 4 February 2014

Week 2

Monday
In the first lesson in week 2, we were expecting a lab session (as Mr Tan told us that the lesson on Monday would be our lab session), so we went as a class to the Science Lab. However, when we arrived there, Mr Tan told us that the labs were occupied on Monday and our lab session would be on Wednesday. I was somewhat disappointed by this as I was looking forward to hands-on activities. Also, our Monday lesson is an hour and a half long while our Wednesday lesson is only an hour long. Thus, we would have half an hour less to be in the lab every week. Mr Tan also seemed slightly annoyed by this as we would have to fit one hour and a half of planned activities in the lab into the one hour session.

So instead of being at the Science lab, doing hands-on activities, we stayed in the classroom and listened to what Mr Tan had planned for us. He split us into five or six groups (can't remember) and handed each group a 'pink monster' (pink paper with strings as limbs). He told us to find out how the strings were connected by pulling the 'limbs'. He also forbade us to look inside the 'pink monster' as there would be no analysis and fun anymore. At first, our group had difficulty seeing which strings moved which as they were often taut. Therefore, after we tried out all the strings once and checked again, we realised that the results were completely different from our first try. We then made sure that the strings were all able to be pulled before actually pulling one string. After about 5 minutes of trying and failing sometimes, we finally decided that the strings were all connected together as whichever string we pulled made all the others move as well. Turns out we were right after Mr Tan revealed the answers.

Mr Tan explained to us that the activity was to show us the limitations of Science. We could not see how the strings were connected from the outside as they were inside the 'pink monster', but could find out by trying out different things on the strings (pulling them). He also showed us how some pupils from another class
found out how the strings were connected by pressing on the 'pink monster' to feel the strings.

We were then shown a set of powerpoint slides on lab safety to prepare us for the lab session on Wednesday.

Tuesday
On Tuesday, we had Science lesson during what should have been English lesson, so as to make up for Mr Tan's upcoming absence on the next Monday.

We learnt about the Scientific method, which is the guideline we follow when conducting an experiment (asking a question, formulating a hypothesis, planning an experiment to find out something, making observations, and from the results, making a conclusion). We also learnt how to start the graph with a number not 0. This is to expand the space available on the graph paper for drawing out the graph. We also learnt about the best-fit line and how to draw it.

The best-fit line is a straight line which is drawn on a graph which has results that form neither a straight line nor a curve. The best-fit line is drawn to distribute equally the points above and below the line.

We also recapped on the independent, dependent and controlled variables in an experiment, and discussed about whether factors which seem like they do not affect the experiment when changed (e.g. Colour of flower pot), should be kept constant.

Wednesday
In our first Science lesson on Wednesday, we learnt about the different apparatus in the Science lab and how they are used, as well as the safety precautions (once again) we have to follow in the lab.

We then learnt how to use the spark gun to light up the bunsen burner. Afterwards, we learnt about the non-luminous and luminous flames, and how to switch in between them after lighting the bunsen burner. When the air-hole of the bunsen burner is closed, the flame that appears is the luminous flame, which flickers around unsteadily and is easily seen. However, when the air-hole is closed, the flame that appears is the non-luminous flame, which burns steadily and at a higher temperature than the luminous flame, but is not easily seen from a distance and might thus might be dangerous if a person is not careful. We also learnt about a "strike back" which is what might occur if the bunsen burner is lit up while the air-hole is open. Basically what happens during a strike back is that the flame coming out of the bunsen burner might be a little green and also gives a toxic gas which is harmful to our bodies. When this occurs, we have to turn off the gas tap immediately so as to avoid breathing in too much of the gas. If we do not do that... who knows what could happen?

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