Water Water Everywhere
The Water MoleculeH2O
WaterColourlessOdourlessTasteless liquid WHEN PURE!!(Minerals in water give it taste)
WaterWater on the planet is found in the seas and
oceans, rivers, lakes, underground aquifers, and frozen in glaciers and the polar ice caps.
Water is essential on earth for the survival of life. All living organisms need water to survive.
Properties of WaterWater has a boiling temperature of 100
degrees celsius, and a freezing point of 0 degrees celsius.
When water freezes it expands, so it’s volume is changing but not its mass. This means that ice is LESS dense than water. This is why ice floats in water.
Properties of WaterWater is a good solventThis means that water is good at dissolving
substances, like the minerals calcium and magnesium and gases like oxygen
This is really important for fish!!!
Properties of WaterWater has a high surface tensionThis is what creates the meniscus in glass,
why raindrops are so big and why insects can walk on the surface of water.
Water molecules have a high attraction to one another, they are always pulling towards eachother. These forces hold the molecules close to eachother.
Water Distribution
Water distributionSome parts of the world suffer severe water
shortages
Water Uses
REMEMBER!!Actual water usage and virtual water usage
are NOT the same!Virtual water usage is much higher! It’s the
food on your table and the clothes on your back!
Water CycleBased on the changing states of waterEvaporationCondensationPrecipitationFreezingMelting
Water Cycle
TidesThe tides are caused by the gravitational pull of
the moon on the earth (and less so the sun)
CurrentsThe currents of the world are an explication
of how the oceans move.There are warm currents and cold currents,
and these can change the climate of an area or cause extreme weather (eg. Ireland being warmer than it should be and El Niño in S. America)
Currents
Water TreatmentWater needs to be cleaned before it can be
consumed by humans. Then after use in homes and businesses, it
needs to be cleaned once again before it can be returned to natural waters like rivers, lakes and the sea.
See: http://www.skoool.ie/content/skoool_learning/junior/lessons/science/water_solutions/flash/h-frame-ns6.htm
Water HardnessWater hardness is down to the presence of
Calcium and Magnesium ions in the water. The more of these ions there are, the harder
the water.Hard water can cause damage to kettles,
washing machines and other appliances that use water.
Water HardnessHard water does not form a lather (bubbles)
easilyHard water depends on the type of rock that
the watter has come into contact with.If you have hard water in your house, it is
because there are rocks underground which contain a lot of calcium and magnesium.
The water passes over these rocks and dissolves the minerals
Water Shortages1.2 billion people in the world today do not
have access to clean drinking water.3.4 million people die each year because of
water borne diseases1/3 of the worlds population will live in an
area of extreme water shortages by the year 2025
VIDEO Blue Gold: The World Water WarsResearch Water Shortage facts and think
about how it can effect your life.
Water ShortagesHow can water be saved?Reasearch what can be done to reduce water
usage
Look into real examples of water depletion like in the Aral Sea
Water PollutionWater pollution can come from many sources:Acid rain from pollution of the atmosphereAgricultureFactories and IndustryPolluted water from homes and businesses
Research ONE of the above for the exam
How can we fight water pollution?
Resources to studySkoool.ie (link on slide 17)Videos on youtube Your notes from classEducaline (you don’t need the scientific
equations)National Geographic has some great info
about water