When you drink with a straw you suck the liquid, creating a vacuum inside your mouth. Nature dislikes voids and the liquid rushes to fill this void.

Hummingbirds do not drink by sucking liquid, but simply by plunging their tongues into the nectar. They drink by capillary action. You can observe this phenomenon when blotting paper absorbs ink or spills, and when sponges soak up water. Did you know that a plant also eats through capillary action? Normal 0 false false false MicrosoftInternetEx Read More
When you drink with a straw you suck the liquid, creating a vacuum inside your mouth. Nature dislikes voids and the liquid rushes to fill this void.

Hummingbirds do not drink by sucking liquid, but simply by plunging their tongues into the nectar. They drink by capillary action. You can observe this phenomenon when blotting paper absorbs ink or spills, and when sponges soak up water. Did you know that a plant also eats through capillary action?

© Musée de la nature et des sciences de Sherbrooke 2007. All rights reserved.

The simultaneous action of the forces of adhesion and cohesion in certain liquids is such that if a material comprised of tiny canals is plunged into it, the liquid in these canals rises to the point where the pressure created by the weight of the column of liquid in a canal on the liquid remaining in the reservoir is equivalent to the atmospheric pressure. This phenomenon is called capillary action.

Adhesion : When molecules have the tendency to adhere to a foreign surface.

Cohesion : The fact that molecules stick together.

The simultaneous action of the forces of adhesion and cohesion in certain liquids is such that if a material comprised of tiny canals is plunged into it, the liquid in these canals rises to the point where the pressure created by the weight of the column of liquid in a canal on the liquid remaining in the reservoir is equivalent to the atmospheric pressure. This phenomenon is called capillary action.

Adhesion : When molecules have the tendency to adhere to a foreign surface.

Cohesion : The fact that molecules stick together.


© Musée de la nature et des sciences de Sherbrooke 2007. All rights reserved.

• a flower (a daisy or another kind)

• a glass of water

• food colouring

Musée de la nature et des sciences de Sherbrooke

© Musée de la nature et des sciences de Sherbrooke 2007. All rights reserved.


Step 1: Color your water

Dilute a few drops of food colouring in a small glass of water.
Step 2: Place the flower in the glass

Careful, your flower has to stand up straight.
Step 3: Observe

The flower drinks the coloured water through capillary action. After a few moments, the inside of the stem takes on the colour of the food colouring. In less than an hour, you will see tiny coloured spots appear on the end of the flower petals. After a full night, the flower will be completely coloured.

Step 1: Color your water

Dilute a few drops of food colouring in a small glass of water.


Step 2: Place the flower in the glass

Careful, your flower has to stand up straight.


Step 3: Observe

The flower drinks the coloured water through capillary action. After a few moments, the inside of the stem takes on the colour of the food colouring. In less than an hour, you will see tiny coloured spots appear on the end of the flower petals. After a full night, the flower will be completely coloured.


© Musée de la nature et des sciences de Sherbrooke 2007. All rights reserved.

Step 1: Color your water

Step 2: Place the flower in the glass

Step 3: Observe

Musée de la nature et des sciences de Sherbrooke

© Musée de la nature et des sciences de Sherbrooke 2007. All rights reserved.


Step 1: Colour your water

Dilute a few drops of food colouring in several small glasses of water (one glass per colour). Step 2: Split the stem

Split the flower stem lengthwise into as many sections as you have colours. Lay the flower on a cutting board; splitting it will be easier. Step 3: Flower-feeding time!

Place each stem section into a different glass of water, and let nature do the rest! You'll have to find a way to hold your flower up.

Step 1: Colour your water

Dilute a few drops of food colouring in several small glasses of water (one glass per colour).

Step 2: Split the stem

Split the flower stem lengthwise into as many sections as you have colours. Lay the flower on a cutting board; splitting it will be easier.

Step 3: Flower-feeding time!

Place each stem section into a different glass of water, and let nature do the rest! You'll have to find a way to hold your flower up.


© Musée de la nature et des sciences de Sherbrooke 2007. All rights reserved.

Step 1: Colour your water

Step 2: Split the stem

Step 3: Flower-feeding time!

Musée de la nature et des sciences de Sherbrooke

© Musée de la nature et des sciences de Sherbrooke 2007. All rights reserved.


The stem of a flower or a plant is composed of many tiny canals. Each canal is linked to a precise part of a petal. Thus, the canal that is plunged into red-coloured water conducts red water to one petal, but not to the others.

Musée de la nature et des sciences de Sherbrooke

© Musée de la nature et des sciences de Sherbrooke 2007. All rights reserved.


Celery

Try different combinations of colours and different flowers. Or experiment with other types of colouring agents diluted in water, such as vegetable juice or ink. You could also repeat the experiment using a stalk of celery or a paper towel instead of a flower.

Musée de la nature et des sciences de Sherbrooke

© Musée de la nature et des sciences de Sherbrooke 2007. All rights reserved.


Learning Objectives

The learner will
  • record observations about the experiment

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