SURFACE TENSION OF WATER

Alumna: María Blanco Blanco

CONCEPT AND OBJECTIVE
The main subject we are going to work on is the surface tension of water. But also there are other cross curricular subjects we want to learn like cooperative work or taking care of friends.
This project is created for children between 3-5 years old



STEPS AND ACTIONS
A) Materials
First, we show children different instruments we are going to use in the experiment like water, jars, bowls or plastic glasses, droppers, clip boxes, and ask them what they would do with those things. We let them imagine experiments with water, discover the capacity of glasses, learn how to use droppers, etc, in conclusion, offer them the opportunity to manage everything.
B) Directed activity
Now, when they have had enough time to recognize different instruments and manage them, we ask them several questions:
- Do you know what water is?
- Where can we find water?
- Is there anything living in water?
- Do you know what water is composed for?
We help them to answer each question with different metaphors. What we want them to understand is the surface tension of water so we start talking about the rain and the drops that fall from the sky. This way they could associate the drops as the minimum unity of water and we had taught them the water composition without talking about molecules or atoms.
Then we ask them to represent water drop by drop: each child would be one drop and we would be connected through hugs. This way we could understand that it someone falls, the others will catch him and if we want to move, we have to walk and dance together like water flows.
At the same time we teach them a chorus:
Drop by drop water flows
Water flows
Drop by drop all togeeether
Drop by drop
Dancing all
Hugging all
Drop by drop
Swimming whereveeeer
Now that we have just understood how water acts, we try to use this information through an experiment by pairs or little groups:
- Experiment: we want to demonstrate this union drop by drop.
- Process:
1. We have got a glass bowl and we fill it up to the top and let the water falls.
2. Then, we ask children about the capacity of the glass bowl, "Can you see this is too much water for this glass?"
3. Now we fill the glass bowl up to the top and finish to fill it up with the dropper carefully.
4. Now we can see how the drops don't fall down because the other ones on the surface of the glass are hugging them. We can observe how the water makes a little arch. Look at it!
5. This happens because superficial drops will hug theses new ones and won't let them fall.
6. On the surface of water, drops build a thin skin like a jumping bed.
7. We can check it by asking children to throw a paperclip into the glass bowl.
We could realize that it goes to the bottom of the glass. But if we place the paperclip carefully on the top on the water, it will float. What happens then?
8. The reason is because of the water skin. This thin water skin is so delicate and it can't take too much weight.
Little bugs could walk on top of the water thanks to this skin or jumping bed!
9. Also there are substances like soap that could break this skin. Look at this!
What happens when I touch this water skin with my soapy finger?
We realize that soap break this water skin, jumping bed or surface tension of water.
10. Another experiment we could make to check this water skin is
- Cover the cup with a tight.
- Add a Little bit of water into the cup.
- Put your hand covering the cup and turn it over.
- After a few seconds, remove your hand.
- You can check that the water is not coming out of the cup.
- This happens also because of the water skin that doesn’t let the rest of the water falls: superficial drops will take care the rest and won’t let them fall.
C) Conclusions. What have we learn today?
We think about our experiments and realize why bugs can walk on water, why some objects could float or not depending on how hard we throw them into the water and also we learn about friendship and affection. Because at the end of the practical lesson, we realize that sometimes water acts like people, if someone comes to hug us slowly with love and care, we usually receive him/her with our arms wide open.
So we could learn about water! Dance, play, hug our friends and remember that anyone would fall if we are there to bring him/her our arms and love capacity!
D) Cleaning up
When we finish, we clean up and dry each object and put they all back on their place.

EVALUATION
We can evaluate ourselves by listening to our students’ conclusions, checking our students’ faces, observing their motivation and their behaviour the following days or asking them to draw what they have learn today. Our main objective was to encourage their curiosity and to wonder why things happen in the world around them.
If we realize our intervention have been too difficult to understand for them, we will have to review the way to explain it or to make it more attractive.