Water Unit
Where is most of the Earth’s water found?
Oceans
What percent of the Earth is covered with water?
Around 70%
What is the hydrosphere?
Hydrosphere includes oceans, rivers, streams, lakes and other bodies of water. The
Hydrosphere also includes water frozen in the polar ice caps and water vapors in the atmosphere.
The prefix “hydro” comes from where and what does it mean?
Hydro come from the Greek language and means Water
What is the water cycle?
The water cycle refers to the constant movement of water. This includes evaporation,
condensation, precipitation, run off and collection
Water quality describes what?
The condition of the water, including chemical, physical, and biological characteristics, usually with respect
to its suitability for a particular purpose such as drinking, swimming, and
sustaining life.
What affects the Earth’s quality of water?
Temperature, pH, Nitrates & Phosphorus, Turbidity, Biological Indicators
Think back to our studied of Ecology “Miracle Fish" and the affects of increased algae in the
water. How can an increase of algae caused by an increase of warmer temperatures have a
negative impact on marine organisms?
Algae are living organisms that absorb oxygen in the water. An overabundance of algae can
cause areas of water to be depleted of oxygen that is needed by other aquatic life forms.
Give an example of how Thermal Pollution takes place.
Any of the following can are examples of thermal pollution:
-Storm water running off of warm streets and parking lots
-Construction along riverbanks removing shading trees increases amount of sunlight.
-Soil erosion increases the amount of solids in water which absorbs more of the sun’s heat
Using the pH scale, at what point do normal adult fish begin to die?
Between 3 and 4
According to what you have read, what can cause an increase in the levels of pH in Earth’s water?
Human interaction causes an increase in Earth’s water quality
Why is Nitrogen an important element among all thing things?
Nitrates or Nitrogen is necessary for protein production in living organism.
What can cause an over abundance of nitrates in Earth’s water?
The burning of fossil fuels has increased the amount of nitrogen oxide and sulfur dioxide released into the
atmosphere. The two combine with moisture in the air and falls as acid rain
What does BMP stand for when discussing water quality?
Best Management Practices (BMP) is a concept farmers have to practice in order to keep fertilizers and
animal sewage out of water.
Too much of the Phosphorus element in Earth’s water can cause what?
Increase phosphorus causes an increase in algae growth.
If a stream has an increase in turbidity, what will the water look like?
The turbidity is greater when water is murkier. Turbidity increases as the suspended solids in water
increases and keeps sunlight from passing through. Clay, silt, plankton, industrial waste and sewage are
things that increase the turbidity or cloudy appearance.
Explain how the increase of turbidity can affect water temperatures and aquatic organisms?
As turbidity increase, the water will become darker and murkier. This will prevent sunlight and heat from
penetrating the surface of the water creating cool spots wher some organism may not be able to survive.
What do Hydrologist and other scientist use to determine the health of water resources?
Biological Indicators
The chemical compound for water is H20. What does this means?
This means that there are two hydrogen atoms bonding with one oxygen atom to create a molecule of
water
What is a Polar Molecule?
A bonding of atoms that have opposite charges
What is the difference between a compound and a molecule?
The difference between a compound and a molecule is a molecule is formed when two or more atoms
join together chemically. A compound is a molecule that contains at least two different elements. In this
case: Hydrogen and Oxygen. All compounds are molecules but not all molecules are compounds.
What is a Solvent?
A solvent is a substance in which some other substance, called a solute, can dissolve to form a solution.
Both the solvent and the solute can be solid, liquid, or gas, but liquid solvents and liquid or solid solutes
are the most common and useful
Why is water considered the Universal Solvent?
Liquid water is often called the “Universal Solvent” because it is able to dissolve more substances than
any other liquid on Earth
Why does it take long for water to heat up than it does a metal burner on a stove top?
The high specific heat of water gives it a high heat capacity. This means that water is capable of absorbing
a great deal of energy.
Why do ice cubes float in water?
Water in the form of ice is less dense than liquid water; therefore, it will float in liquid water.
Hydrosphere
Anything related to water is a part of the hydrosphere.
Evaporation
The phase change that occurs when liquid water acquires enough heat energy to form water vapor.
Condensation
The phase change that occurs when water vapor loses heat energy to form liquid water. It is generally
brought about by a fall in air temperature.
Precipitation
Literally “to fall out of.” In nature, precipitation may take the form of rain, snow, hail, and sleet. Frost is
not precipitation, but occurs when water vapor changes directly from a gas to a solid.
Collection
When water (in any form) returns back to Earth as precipitation. it may fall back (collect) into the
rivers, lakes, oceans or may end up on land.
Water Quality
Describes the condition of the water, including chemical, physical, and biological characteristics, usually
with respect to its suitability for a particular purpose such as drinking, swimming, and sustaining life.
Temperature
A measure of molecular motion, generally using a Fahrenheit (F) or Celsius (C) scale.
Thermal Pollution
Thermal pollution is caused by adding relatively warm water to a cool body of water
pH
A way of describing the acidic or basic strength of a solution. The pH value of a solution is a number
on a scale from 0 to 14.
Turbidity
Turbidity is the measure of the clarity or clearness of water
Biological Indicators
Living organism that help scientist determine the health of water resources
Cohesion
Cohesion is the attractive force between water molecules.
Adhesion
Adhesion is when a molecules of water is attracted to other substances.
Solvent
a substance in which some other substance, called a solute, can dissolve to form a solution.
Capillary Action
is the process that moves water through narrow porous (passages where water can move through)
spaces.
Specific Heat
Is the amount of heat needed to raise the temperature of one gram of a substance by one degree
Celsius.
Density
is measure of the mass of a substance contained in a given volume.
Buoyant or Buoyancy
refers to a material that floats