3. Pre- Primary School
Once upon a time there was a little drop. His name
was…Droppie. He visited different schools in Greece, in Spain
and in the Czech Republic. He wanted to tell us his story. And the
story goes on like that…
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10. Wich is the model who explain the
variation of water temperature?
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16. Water, the chief constituent of living matter and the
environment in which we live, is one of the most
important chemical substances. Ordinary water,
which is impure, usually contains dissolved salts
and gases and sometimes organic matter.
For chemical work water is purified by distillation,
and for the preparation of very pure water,
distilling apparatus and vessels made of fused silica
are used.
Secondary education
17. Pure tin vessels and pipes are often used for storing
and transporting distilled water.
The physical properties of water strikingly differ
from those of other substances. Water can be
characterized as a clear, transparent liquid,
odorless, tasteless and colorless when in thin layers
but in thick layers having a bluish green color.
Very specific for water are its boiling and freezing
points. 0 ° C and 100 °C are temperatures at which
water freezes and boils, therefore these
temperatures serve as a means of identifying water.
18. Water is the only naturally occurring inorganic
liquid, and it is also the only chemical substance on
the Earth that occurs in all three states of matter –
solid, liquid, and gaseous.
The gaseous form of water is called steam. When
gaseous water is mixed with other gases, as in the
air, we speak of it as water vapor, when unmixed,
we call it steam. Water may exist as steam a
temperatures lower than 100 °C, provided the
pressure is less than the usual atmospheric
pressure.
19. If water is cooled sufficiently, it solidifies at 0 °C to
ice. There is considerable expansion during the
solidification, and consequently ice is lighter than
an equal volume of water.
When we apply heat to ice, it melts.
20. • Osmosis is the passage of the water through the
cell membrane.
Experience to explain de osmosis
21. • What happens if you add salt water to a plant?
I start whit a question:
22. • I propose water the plant with salt water seven
days