Station 1
Water is vital for life and has many unique properties. Did you know that a human body is over
70% water? It is important to conserve fresh water because it is very limited on Earth. In fact
only 3% of Earth’s water is drinkable and of that 3% that is drinkable over 75% is frozen in the
polar icecaps. That why it is very important to conserve the fresh water we have on Earth.
Most people around the world have access to clean drinking water but it is a major problem in
poorer areas of the world. Water pollution and low quality water can lead to dangerous bacteria,
disease and viruses such as E coli and Cryptosporidium. Also 87% of New Jersey’s population
obtains its drinking water from a public water system and 13 % from private residential wells.
Station 2
Roles of Water
#1 Affect on Weather
All weather is related to water. Water is in a constant cycle from Earth’s surface to the
atmosphere, where it may form clouds. Water returns to the Earth’s surface as rain, snow, hail,
or sleet. Weather also depends on the amount of moisture in the air.
#2 Water Shapes Earth’s Surface
Water can completely reshape a landscape. Water wears away rock and carries away
sediment and soil. Rivers and oceans change the landscape of an area. Glaciers, for example,
scrape away rock and soil, leaving the sediments elsewhere when the glacier melts.
# 3 Supporting Life
All living things rely on water. Water regulates temperature and helps transport substances in
the body. Without water, all organisms will dehydrate and die. All biological processes depends
on water to function properly.
#4 Supporting Human Activities
We use water for bathing, cleaning, watering lawns and gardens. We need water to carry out
our basic needs. We use water to manufacture goods, cool power stations, and generate
energy. More water is used for agriculture than industry so we can irrigate/water crops and care
for farm animals.
Station 3
Structure of a Water Molecule
All matter (things) are made up of tiny particles called atoms. Atoms can join together to make
molecules. A water molecule is made up of two hydrogen molecules and one oxygen molecule.
The hydrogen molecules link together with the oxygen molecules to make a shape like Mickey
Mouse.
A water molecule is special because it is a polar molecule. Polarity means that one side of a
molecule has a positive charge and a negative charge at the other (like a magnet.) The oxygen
molecules in water are partially negatively charged while the hydrogen is partially positively
charged. Therefore a water molecule is polar meaning the positive side of one water molecule
is attracted/pulled toward the negative side of another water molecule.
Station 4
States of Water
Water exists in 3 different states all with the chemical formula H20. When water changes states
it releases or takes up energy.
Liquid water: Most of Earth’s water is in the liquid form. Earth is the only planet in the solar
system with abundant liquid water which we need to support life. Gravity causes water to run
downhill and liquid water takes the shape of whatever contains it.
Solid water (ice): Liquid water can freeze into solid water called ice. Unlike other liquids, water
actually expands when it freezes. There is more open space between the water molecules in
ice than in water. This is one of the only substances where its solid state is less dense than its
liquid state. This is why ice floats in water.
Water vapor (gas): Water vapor is a gas, so most water vapor is found in the atmosphere.
Water vapor cannot be seen. Clouds are formed when water vapor condenses into liquid water
droplets. Like all gases, water vapor expands or contracts to fill available space.
Station 5
Properties of Water (Station 5)
The first property of water is COHESION. Cohesion is the property that holds molecules of the
SAME substance together (like water molecules sticking to other water molecules.) Water
molecules stick closely together because of their polarity (that attraction/magnet.) Examples of
this is when water comes together to form droplets when it rains. Another example is water
being able to fill a glass above the brim (making a dome shape) without spilling over the sides.
Insects can also walk on water without breaking the cohesion of water molecules because the
molecules stick together.
Water also has a high level of surface tension. Water molecules especially cling to each other at
the surface because there is no water molecule on the other side of them to grab on to. The
water molecules on the surface holds on to each other so tightly that a “skin” seems to form on
the surface.
Station 6
Properties of Water (Station 6)
The second property of water is ADHESION. This is the property that holds molecules of
DIFFERENT substances together. Examples of adhesion include:
Paint stays on your walls.
Water adhering to your skin makes it wet.
Bubble gum sticks to almost anything dry.
Peanut butter sticks to the roof of your mouth.
Water is attracted to other POLAR molecules. These substances are called “wettable” because
water sticks and adheres to it like paper towels or napkins. Water drops will roll off unwettable
or waterproof surfaces which are made up of non-polar molecules.
(Use capillary action as one of your examples) Capillary action is also a result of surface tension
and adhesion. This happens in plants when they "suck up" water. The water adheres to the
inside of the plant's tubes, but the surface tension attempts to flatten it out. This makes the
water rise and cohere to itself again, a process that continues until enough water builds up to
make gravity begin pulling it back down.
Station 7
Properties of Water (Station 7)
The third property of water is SPECIFIC HEAT. Specific heat is the energy needed to heat a
substance by a particular amount. The specific heat of water is the amount of heat needed to
raise its temperature a certain amount. One of water's most significant properties is that it takes
a lot of heat to it to make it get hot. Precisely, water has to absorb 4.184 Joules of heat for the
temperature of one gram of water to increase 1 degree celsius (°C).
The specific heat capacity of water is much higher than that of other common substances. For
the sake of comparison, the specific heat capacity of oil is about 0.5 cal/(g°C) and the specific
heat capacity of aluminum is about 0.2 cal/(g°C). This means that it takes a lot more heat to
raise the temperature of water compared to the amount of heat it would take to raise the
temperature of oil or aluminum.
Water has high specific heat because the attraction between the water molecules is so strong
that it takes a great deal of energy to separate them. Because of its high specific heat, water
can absorb more energy than many other substances can. The ability of water to store and
release heat is very important in weather and climate.
Station 8
Properties of Water (Station 8)
The fourth property of water is that it is the Universal Solvent. A liquid that dissolves
substances is called a solvent. Water is called the universal solvent because more substances
dissolve in water than in any other chemical. This has to do with the polarity of each water
molecule. The hydrogen side of each water molecule carries a slight positive charge, while the
oxygen side carries a slight negative charge. This helps water separate other molecules into
their positive and negative ions. The positive part of an ionic compound is attracted to the
oxygen side of water while the negative portion of the compound is attracted to the hydrogen
side of water.
Most substances will eventually dissolve in water. Any substance that dissolves in water is
polar, since water itself is polar. But that means that any non-polar substance such as oils or
waxes will not dissolve. Water as a solvent is very important to living things. Most of the
chemical reactions that take place inside organisms involve substances dissolved in water.
Station 9
https://m.youtube.com/watch?v=CT4pURpXkbY&list=PL90oavrVuUhVDd3mIvOPLoesd2mHsu6
Hw&index=1
Station 10
https://m.youtube.com/watch?v=aVmU3CLxvgU