A1 On which surface of the leaf did most bubbles appear?
A2 The bubbles contained gas that came out from inside the leaf.
Which part of the leaf do you think the gas came from? (Look at
the diagram of the inside of the leaf above.)
A3
Suggest how the gas got out of the leaf.
A4
Use what you know about the effect of heat on gases to explain why
the gases came out of the leaf when it was put into warm water.