The document summarizes some key features of air through descriptions and experiments. It notes that air is colorless, odorless, and tasteless, yet has weight and fills all space. Experiments are described to show that air prevents water from passing through an upside down cup until it is tilted, and that air pressure keeps a card from sinking when placed on water in a beaker. Further experiments demonstrate air's ability to dry a coin submerged in water and how heated air in a glass lifts water. The document concludes by describing a homemade greenhouse and how it works to trap heat from the sun using aluminum foil and black cardboard around jars.

1. Features of air
3 “v” class, Krasimira Krondeva and Natasha Djurkova
SOU Ekzarh Antim I
Kazanlak, Bulgaria
TOPIC:
Presented by

2. Life is impossible without the air we breathe.It is everywhere around us.
The air posses a number of features:
 colourless gas;
 penetrates everywhere;
 has no taste;
 has no smell;
 has weight;
 fulfills space;
 lighter than water;
 keeps the fire burning.
With the help of the next experiments we will prove some of it`s features.

3. Feature 1:
The air fulfills space
Necessary materials:big vessel full of
water,glass cup,a piece of newspaper

4. Try 1:Place at the bottom of the cup the newspaper, smashed into a ball.After that
dive the whole cup in the water. After a time pull the cup out,without tilting it.

5. Goal:After you take the cup out, the newspaper must stay dry because the
air doesn`t let the water pervade.The air fulfills space.

6. Try 2:Place at the bottom of the cup the newspaper, smashed into a ball. After
that dive the whole cup in the water. After a time pull the cup out,but this time
tilt the cup.Are there any bubbles coming out?
Conclusions:
1.There is air in the bubbles coming out out of the cup;
2.This time the newspaper will get wet,because the air,which has
come out,has set free a space.

7. Air Pressure Water and Gravity
Materials: a simple beaker and an index card

8. Action:
Fill the beaker with water. Then place the card on top of it

9. Hold the card with your hand and hold the beaker.

10. You probably expect that the water will push the card
and will spill all over but it doesn't.

11. This is because the air has pressure which pushes
the card to stay in place. Moreover, the beaker has
a perfect seal and the air doesn't penetrates in
the beaker.

12. Air Pressure Stops the Water In the Bottle
Materials: a water bottle and a pushpin

13. Action:
The bottle is full of water.
Create a hole in the bottle with the pin.

14. The water doesn't come out.

15. What will happened if you open the cap?

16. the water will start coming out
This is because of the cap, which stops the air from getting in the bottle and pushing
down on the liquid. Take the cap off. The air comes in and forces the
water out. When you put the cap back, the liquid stops flowing from the hole.
This is because the air from the outside pushes on the hole and when the cap is
off the air applies pressure on the water and the water comes out from the hole.

17. How to get a coin out of water without getting wet
Materials: a plate, a coin, a glass cup and a candle

18. Action:
Place a little water in the plate.
If you want put some paint in the water so that you
can see the try better.
Then put the coin in it.

20. Put the candle at the middle of the plate

21. Light the candle

22. After that place the glass cup on top of it.

23. The heated air in the cup will soak up the water.
The coin is dry and you can take it without getting wet.


24. The air has weight
Necessary materials:
scales(light stick,hanged to the middle with
thread),2 balloons

25. To the two ends of the stick tide 2 equally inflated
balloons, so that the scales can be balanced. Then
discharge the air in one of the balloons. To which
side do the scales tilt?
Conclusion:The scales tilt to the side with the
inflated balloon, because the air has weight.

26. Greenhouse

27. The greenhouse makes the life on Earth possible.The natural hothouse gases like
water vapor(H2O),carbon dioxid(CO2),a smal quantity of methane(CH4), nitrous
oxide (N2O) and troposferic ozone(O3) allow the sun energy to penetrate and
reach the Earth,and then seize it as an infrared heat.This phenomen keeps our
planet warm enough so that all living organisms may function physiological. The
lack of greenhouse would reduce Earth`s temperature with about 33o C,turnig it
into a planet with no life.Unfortunately over the last century the greenhouse has
become serious threat,because of its augmentation as a result of man`s
activity.The industrialization and the continued growth in the population rapidly
increase the issues of hothouse gases by burnig organick fuels,cutting down
forests and clearing areas for farming purposes.These extra permanent sources
upset the delicate balance,as considerably increace the quantity of hothouse
gases in the atmosphere and increase their warming effect.As a result there is
change in the klimath,a direct influence on human health and changes in the
environment.

28. Necessary materials for making
greenhouse:
 Two jars with screw caps
 Two thermometers(which can be put
inside the jars)
 Aluminium folio
 Black pasteboard
 Chronometer

29. Action:
1.Envelop jar 1 with folio from the outside.
2.Envelop jar 2 with black pasteboard from the
inside.
3.In both jars put a thermometer,then close
them with a screw.
4.Begin to cut time(3 minutes).
5.Watch and see!