Change the colour of celery leaves in this simple experiment.
Things Required:
1 stalk of fresh celery with leaves
Green food colouring
1 clear drinking glass
Directions:
Fill the glass about one-quarter full with water. Make a dark green solution by adding food colouring to the water. Cut across the bottom end of the celery stalk with a knife. Stand the cut end of the celery in the coloured water. After 24 hours observe the colour of the leaves.
This Is What Happens:
The pale green leaves are now a dark green.
Science Behind It:
All plants have tiny tubes in their stalks. The coloured water moves up through these tubes to the leaves. The water is pushed upward by the air pressure in the room. The pressure inside is less than outside the tubes; thus, the coloured water is pushed up to the leaves. The movement of water up through tiny tubes is called capillary action.
