The third time I participated in this activity, I could remember, there were around 1 or 2 experiments that were repeated if I remember correctly. But the others were new and interesting enough to make me go back for a fourth session. I like the way on how the organizers actually provide us with enough apparatus and chemicals for us to try repeatedly even if we failed in the first try. Also it was nice to carry out the experiments at our own speed as some of us liked to rush through or go slow. For me, I preferred going fast because after I observed the results there was nothing much to see anymore, unless I had to try again.
MOVING AIR AROUND
I had heard of this hair-dryer-ping-pong-ball experiment, but never really tried it before because when I had a ping pong ball I didn’t have a hair dryer and vice versa. Well when this time I tried it, it worked perfectly fine. Apparently due to Bernoulli’s principle the faster speed caused by the moving air created a lower pressure which prevented the ball from being flung away out of the air stream. That is the same principle used in aircraft to create lift and also for propeller planes.
HUMAN BATTERY
Before this experiment I knew that our body conducts electricity, well that is how we get electrical shocks when we touch power sockets or some electrical source. But I didn’t know why there was this copper and aluminium plates for us to put our hands on. I think it has something to do with the polarity of the batteries or something like that. I felt a tingling sensation then because of the current flowing through my hands.
EYE MODEL
The experiment simulated what happens in our eye. There was the water which symbolized the vitreous humour and the white plate and lenses that represented the optical disc and the retina. So I learnt that the image was inverted in many types of ways because of the various lenses we use to correct short-and-long-sightedness.
TORNADO TUBE
Probably the most fun experiment there, it simulated vortices which look like tornadoes in the bottle. It was fun to see the liquid flow down and when I stopped the vortex the air was unable to rise up and the liquid stopped flowing down. Apparently some of Bernoulli principal was used in the experiment because of the difference in air pressure at the base and at the top of the vortex.
TOP SECRET
This felt like a weird experiment because I couldn’t seem to get it right. Every time I spun the top, it would like go off course and spin off onto the table. Thus I had to just watch others spin it and observe. I think the experiment has to do with some electromagnets and polarity and it repels the top to the end of the cone when spun. The top probably became a magnet when spun.
PINEAPPLE GELATIN
This was an experiment that was repeated. The last time I had problems measuring the 2ml of the pineapples because the pineapple stuck to the dropper, making it very difficult to see the 2ml mark and even worse, most of the droppers were broken at the top losing all the pressure and making it useless. Thus I had wrong and different results as compared to the previous experiments.
LAVA LAMP
I didn’t know lava lamps worked that way, because they would probably use up all the Alka-Seltzer tablets after 5 minutes or something. This experiment was very interesting as it was very beautiful to look at, and it shows how air can carry the water to a lesser dense liquid like oil, then dropping back to the bottom when the air bubble is released into the air.
BLUE BOTTLE
This experiment was a bit confusing because the chemicals used were new to me, like methylene blue solution. Anyway, I learnt that solutions will change colour when vigorously mixed with oxygen. It is quite amazing on how the solution changes colour when we shake it and return to normal when the oxygen is released back.
ADSORPTION OF HEAVY METAL IONS
I went to check adsorption when I went home and adsorption is when a solid or liquid sticks to a surface. So I’m guessing that the copper (II) had been adsorbed onto the orange peel and thus the lesser amount of copper (II) in the readings after. I didn’t know that there was a machine to measure copper (II) and the concentrations of other materials until I saw it. It was quite complicated and sophisticated.
Overall, I had enjoyed my time in the lab doing experiments and I hope to go for future science for fun sessions to carry out experiments.
Shao Xuan
(Post #7)
