Diapositiva 1

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Water A really strange molecule
Experiments with water
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Why water?

• Water is one of the most amazing molecules
• Water is an aparently simple molecule (H2O) with
  a highly complex character

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Density
Density

• One of the main properties studied is density. In
  the exercises the students learn how water
  changes of density produce or influence a great
  variety of natural phenomena

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• Water is almost unique among the more than 15
  million known chemical substances in that its
  solid form is less dense than the liquid.
• The large increase (about 9 under atmosferic
  pressure) on freezing shows why ice floats on
  water and why pipes burst when they freeze. The
  expansion between 4 and 0 ºC is due the
  formation of large holes when all the molecules
  fit together.  

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Teaching-learning sequences

• Designed to help students to gain awareness of
  the importance of water proprerties and their
  implications.
• Based on the use of experimental activities that
  include simulations.
• Designed specifically to help pupils reflect on
  the experiments and extend their analysis to
  wider situations.

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Lesson 1 Laboratory glassware

• In this lesson the students learn the names of
  different items they will use in the rest of the
  lesson, while making experiments.
• They use dicotomic keys to classify the items and
  work on observation to decide how to classify and
  describe them

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Laboratory glassware
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Lesson 2 The thermocline and El Niño
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The thermocline

• First there is an activity to visualise what the
  thermocline is and how the temperature
  differences make hot and cold water react is if
  they were different substances.

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ENSO phenomenonNormal conditions
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ENSO phenomenonEl Niño
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ENSO phenomenonLa Niña
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Upwelling.

• Upwelling is very important because the nutrients
  that normally are in the bottom of the sea are
  transported to the surface and this allows the
  food web to grow.
• This is a phenomenon which normally happens in
  the coast of Perú. Are the Peruvian fishermen
  happy with this situation? Why?

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Upwelling

• What happens in El Niño situation?
• What happens in La Niña situation?
• How is fishing in the Peruvian coasts affected?

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Lesson 3 The icebergs

• What happened to the Titanic?

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The icebergs solid floating on liquid
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How could an iceberg destroy such a huge ship?

• Are icebergs are made of salt or fresh water?
  ____________ water.
• You know that we are not seeing the whole
  iceberg. The part under the water is
• Bigger than the one on the surface
• Equal to the one on the surface
• Smaller than the rest of the iceberg

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Fresh water or salty water

• Silver nitrate test

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Iceberg formation
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Icebergs and ice packs

• What is the difference?
• What happens in the Artic, are there icebergs and
  icepacks?
• And what happens in the Antartic?

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Application exercise
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What will happen to the bears?

• What will happen when the ice you see in the
  picture melts? Tick the ideas that are correct.
• The polar bears will get wet
• The level of the sea will increase
• The level of the sea will diminish
• The level of the sea will not change
• The changes in the sea level will depend on where
  the ice came from

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Design an experiment
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How could an iceberg destroy such a huge ship as
the Titanic?

• Tricky question!

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Dew, clouds, fog and smog
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Dew point
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How and why dew forms?

• Why does water vapour turn into liquid?

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Convection
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Condensation
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How are clouds and fog formed?
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Fog and smoke smog
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Water cycle
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Where is the water?
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The water cycle in a bottle
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Water table or Groundwater level
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Labeling the hydrological cycle
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Evapotranspiration
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Sea-water intrusion
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Why is this water cycle better than other
representations?
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What is still lacking?
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Here it is where?