Science Question 1 - bubbles

I think there was once when we went to the fish tank and Cong Wei spotted bubbles from the leaves.
This pupil asked the same question and this is the explanation.

Question No. 19627 :
I rear some fishes at home and I place a few water plants in the tank. Recently, while feeding the fishes, I observed that there are some air bubbles on the leaves? Why is it so? What do these air bubbles contain? Why is it that the air bubbles do not float onto the surface of the water, as air is less dense than water? Thanks.

Water plants undergo photosynthesis when light shines on them. As a result, oxygen gas is released. The tiny bubbles you saw on the leaves contain oxygen. When a bubble is too small to provide an upward floatation force big enough to overcome the surface tension between the bubble and the leave, it adheres to the surface of the leave. As it becomes bigger, it will float to the surface of the water. This is a common experiment carried out by students in the laboratory to study photosynthesis.


For additional information, please refer to the follow URLs:

http://www.learn.co.uk/default.asp?WCI=Unit&WCU=3539

http://www.courseworkbank.co.uk/coursework/rate_photosynthesis_1955/

http://www.learning-connections.co.uk/bectascience/intranet/
activity/photo.html

Question Asked By:
Name: Goh
Age Group: 13 to 20
Occupation Type: Student
Education Level: Primary