Tuesday, April 28, 2009

Datalogger Experiment

The datalogger can be used for testing unseen substances. Like: Heat, Gas, etc. We used the gas sensor for the experiment. It turned out that our leaf gave out CO2 when they photosynthesised. Firstly, we adjusted the time to automatically stop after 30 mins, next, we put a leaf in a jar. Third, we put the sensor on the jar, like a lid. The leaf was not from our own sunflower. It was from the additional sunflower that were grown. Our sunflower's leaves were too small. We observed the chart of the datalogger. We forgot that the sensor was not supposed to be on the lamp, as it was too hot. So we restarted everything. The graph showed that carbon dioxide levels were decreasing after a while. After half an hour, we saw tiny water droplets on the inner surface of the jar. So, plants give out water vapour which caused the 'misting'.

Tuesday, April 14, 2009

PBL Lesson -- Checking and Action

Prediction:Our prediction was that the flower to be half red half blue.We also wanted it to be straight.

Observations: The edge of the flower was blue, and the stalk was red and blue.It was drooping. The tape was not sticky enough to hold the plant in place. It turned out to be like that because the tape touched the water a little hence lost its' stickiness.Blue water was absorbed faster than red water.

Ying Xuan's sunflower(the Taiwan seed), is very short. It looks as though it is broken... :(
Abigail's sunflower: (the Singapore seed), is quite tall. It is 28 cm. But too bad,it has not grown any flowers!!!!!!! :(