20.9.11 - Lab activity @ Pusat Sains Negara

For our lab activity at Pusat Sains Negara, we did the following activities / experiments.
1) Testing for Starch
2) Testing whether a substance is acidic, alkaline or neutral
3) From Flower to Star
4) Flower blossom

1) Testing for Starch
Scooping items into the micro well to test for starch - We tested sugar, wheat flour, corn flour,  biscuit and baking powder by putting one or two drops of iodine solution into the micro well.
Squeezing iodine drops
If starch is present, the substance will turn dark blue / black.
2) Testing whether a substance is acidic, alkaline or neutral
Substance for testing: vinegar, detergent, toothpaste, sugar, lime juice, salt, shampoo and baking powder

Various items for testing
Squeezing in liquid detergent into the micro well
Add in a few drops of water
Put in the red and blue litmus paper. If the red litmus paper turns blue,  the substance is alkaline.  If the blue litmus paper turns red, it is acid.

3) From flower to star - Learning about water absorption
Bend into two, 5 toothpicks (but don't break them). Arrange in a circular container in the pattern shown above. 
Squirt water in the middle of the 'flower'. Watch it slowly move and change into a star. 
According to the facilitator, the bamboo toothpicks absorb the water and expanded, thus pushing outwards until their outer tips touched one another, to become a star. (I had initially thought that the water pushed the toothpick outwards). 
A star
4) Paper Flower blossomming - Learning about water absorption

Fill the circular container with water until it is half full
Put in the piece of paper 'flower' that has been folded flat. Watch it open up. The paper flower opens up due to water absorbtion. 

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