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