2. ‘The Earth Is Our Little Green House’

3. Water …

4. INTRODUCTION… Water is essential for life! No living creature can live without it. It doesn’t have any shape- it gets the shape of a container in which it is placed. You can find water in the oceans, seas, lakes and rivers all over the world. Water covers 2/3 surface of our globe. Water consists of chlorine and hydrogen. In nature you can find water in 3 states of aggregation: solid (ice), liquid (liquid) and gas ( water steam)

5. Amazing water drop…

6. EVAPORATING You need: - 2 tissues - Water What to do…? 1.Take two identical tissues. 2.Dip them in water. 3.Fold one of the tissues four times. This way you will make its surface smaller. Let’s call it ‘tissue A’ 4.Unfold the other tissue. We will call it ‘tissue B’. 5.Place both tissues in the sunlight. What can be observed? Tissue B dries faster than tissue A. How to explain that? Tissue B wasn’t folded and so the sun could reach to greater surface and water was evaporating faster. In case of tissue A the sun was shining only on ¼ part of its surface. That’s why evaporation process was much longer.

7. Water steam condenses… You need: -A kettle -A burner -Water -A metal container -Ice cubes and water cold as ice. What to do…? 1.Pour water into the kettle and heat it on the burner. 2.Wait as long as it starts to boil. 3.Into the metal container pour ice-cold water and throw some ice cubes. 4.When some steam starts to appear above the kettle, bring the metal container closer to it. What can be observed? On the outside surface of the metal container water drops appear. How to explain that ? Touching the cold surface water steam condenses. The metal container had a much lower temperature than the boiling water in the kettle, water steam after ‘coming into contact with’ cold surface changed into drops.

8. Water drops…

9. In a solid state water takes much more place … You need: -A plastic container with a lid -Water of room temperature -Freezer What to do…? 1.Fill the container with water to the brim. 2.Place the lid on the container but make sure it isn’t firmly on. 3.Place everything in the freezer and wait 5-6 hours till the water freezes. What can be observed? Water froze and it sticks out of the jar when we lift the lid. How to explain that? Changing the state of aggregation from liquid into solid, water increases its capacity. In the form of ice it takes more place and the container can’t hold it.

11. Salty water isn’t good for plants… You need: -Two healthy potted plants -Normal water -Salty water What to do…? 1. Place the potted plants. Let’s call them A and B. 2. For one week water plant A with normal water and plant B with salty water. What can be observed? Plant A develops healthily. Plant B is sick and it already withers after a few days. How to explain that? Salt contains such chemical substances like sodium and chlorine. And they are not good for the growth of the plants. Even for people too much salt is unhealthy. It can cause health problems like for example hypertension.

13. Taking up water by plants… You need: -A jar -Water -Dark red ink -A dropper -Celery with leaves What to do…? 1.Fill the jar with water. 2.Using the dropper add a few drops of ink so that it clearly coloured the water. 3.Place the celery in the jar with water. 4.Place the jar in a warm place. What can be observed? After a few hours the celery and its leaves turned red. How to explain that? The celery stem took the colourful water and transferred it to the leaves. In nature the plants take water from soil through their roots and deliver it to all the parts.

15. FACTS… At windy weather water evaporates faster. Water can be cleaned in many ways. Rain is the ‘successor’ of evaporation. Rain drops are round. Lots of diseases like diarrhoea, dysentery or cholrea spreads through water. Underground, closed water supplies are called artesian waters. Water drops which freeze on the Earth surface create black ice. Water constitutes 70% of a human body. The most humid part of the body is an eye which consists of 99,68% of water. Molecules of evaporating water stay in the air for almost 10 days. Water covers about 70-75% of the Earth surface.