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Chapter 7 Unit Test


Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.
 

 1. 
The pH of water is a measure of its
a.
saltiness.
b.
acidity.
c.
color.
d.
cloudiness.
 

 2. 
Pure water is neutral, meaning it is neither an acid nor a base. Pure water has a pH of
a.
0.
b.
14.
c.
7.
d.
10.
 

 3. 
The first step in treating water from a river or lake is usually
a.
chlorination.
b.
coagulation.
c.
concentration.
d.
filtration.
 

 4. 
The amount of one substance in a certain volume of another substance is its
a.
concentration.
b.
coagulation.
c.
filtration.
d.
desalination.
 

 5. 
Why is chlorine added to drinking water?
a.
Chlorine improves the taste of water.
b.
Chlorine softens hard water.
c.
Chlorine kills disease-causing microorganisms.
d.
Chlorine prevents water from becoming cloudy.
 

 6. 
What enables water to move through a system of pipes?
a.
hardness
b.
water pressure
c.
pH
d.
water quality
 

 7. 
Household wastewater and the wastes in it are called
a.
sewage.
b.
flocs.
c.
sludge.
d.
gray water.
 

 8. 
Many homes that are not connected to public sanitary sewers might dispose of sewage using a(n)
a.
aquifer.
b.
septic system.
c.
reservoir.
d.
well.
 

 9. 
A drought is a long period of
a.
heavy, damaging rains.
b.
unusually hot weather.
c.
less rainfall than normal.
d.
rain coming late in the year.
 

 10. 
The process of obtaining fresh water from salt water is called
a.
desalination.
b.
filtration.
c.
conservation.
d.
coagulation.
 

 11. 
Which of the following is a way to conserve water?
a.
taking longer showers
b.
reusing water in a factory to cool hot machinery
c.
letting the water run while you brush your teeth
d.
using open ditches to carry water for irrigation
 

 12. 
Using water wisely to avoid wasting it is called
a.
desalination.
b.
distribution.
c.
conservation.
d.
irrigation.
 

 13. 
Specific sources of pollution that can be identified are called
a.
point sources.
b.
nonpoint sources.
c.
runoff.
d.
sewage.
 

 14. 
Which of the following is NOT a major source of freshwater pollution?
a.
human and animal wastes
b.
industrial wastes
c.
wetlands
d.
agricultural chemicals
 

 15. 
A type of water pollution that is caused by smoke and exhaust is
a.
sewage.
b.
heat pollution.
c.
acid rain.
d.
road runoff.
 

 16. 
Pesticides are most likely to be found in runoff from
a.
roads.
b.
farm fields.
c.
homes.
d.
factories.
 

 17. 
A pollutant often found in road runoff is
a.
sewage.
b.
pesticides.
c.
oil.
d.
industrial chemicals.
 

 18. 
An example of how living things can help clean up polluted water is
a.
pumping polluted groundwater to the surface and cleaning it.
b.
allowing the rock in an aquifer to naturally purify groundwater.
c.
avoiding using fertilizers on lawns or gardens.
d.
adding oil-eating bacteria to water polluted by an oil spill.
 

 19. 
Which of these examples is a water-conservation technique that also reduces water pollution?
a.
factories making printing inks with water instead of chemical solvents
b.
farmers using fewer pesticides on farm fields
c.
factories reusing cooling water instead of returning it to a river
d.
farmers planting fields of coarse grass that filter out pollutants
 

 20. 
The energy that carries a kayak along in a swift river is
a.
kinetic energy.
b.
potential energy.
c.
stored energy.
d.
electrical energy.
 

 21. 
Energy that is stored and waiting to be used is
a.
kinetic energy.
b.
potential energy.
c.
electrical energy.
d.
mechanical energy.
 

 22. 
When the floodgates open, the potential energy of the water behind the dam is changed into
a.
chemical energy.
b.
stored energy.
c.
kinetic energy.
d.
gravitational energy.
 

 23. 
One benefit of hydroelectric power plants is that they
a.
are inexpensive to build.
b.
do not cause air pollution.
c.
depend on fossil fuels.
d.
can be built in any location.
 

 24. 
What is one way that dams affect living things in a river?
a.
Dams supply water for irrigation.
b.
Dams give salmon and other fish room to swim farther.
c.
Dams send extra nutrients farther down the river.
d.
Dams prevent fish from traveling to the place where they lay their eggs.
 

 25. 
What is one disadvantage of building dams?
a.
They flood large areas of land, sometimes forcing people to move.
b.
They provide electricity for many people.
c.
They supply water for irrigation.
d.
They can help in controlling floods.
 

Modified True/False
Indicate whether the sentence or statement is true or false.  If false, change the identified word or phrase to make the sentence or statement true.
 

 26. 
The runoff from fertilizers pollutes ponds and lakes and slows down eutrophication. _________________________

 

 27. 
During drinking water treatment, unwanted particles form clumps known as flocs in the process of filtration. _________________________

 

 28. 
The wastewater and wastes in it that are produced in homes are called sewage. _________________________

 

 29. 
A water shortage occurs when the demand for water is less than the supply. _________________________

 

 30. 
In general, hydroelectric plants cause more air pollution than power plants that burn coal or oil. _________________________

 

 31. 
A pipe spilling chemicals from a factory into a river is an example of a point source of pollution. _________________________

 

 32. 
Preventing water pollution is often easier than cleaning up pollution. _________________________

 

 33. 
Water stored behind a dam has kinetic energy before it is released. _________________________

 

 34. 
Although building a hydroelectric power plant is expensive, water is naturally renewed by the water cycle and is free. _________________________

 

 35. 
Electricity produced by water moving over a waterfall or through a dam is called kinetic power. _________________________

 

Completion
Complete each sentence or statemen using one of the following wordst.

chlorine            acid rain      aquifiers      pesticides      bacteria/organisms
filtration            kinetic            dam            drought      primary treatment
fertilizer            habitats            pH            desalination      hardness
water pollution/      concentration      collapse/      hardness      iceberg/ice
pollution                        sink
 

 36. 
The first stage of treating wastewater, called ______________________________, involves the removal of solid particles.
 

 

 37. 
The first step in treating drinking water, called ____________________, involves passing water through a series of screens.
 

 

 38. 
The ____________________ of water is a measurement of how acidic it is, on a scale of 0 to 14.
 

 

 39. 
The amount of one substance in a certain volume of water is called its ____________________.
 

 

 40. 
A period of less rain than normal in an area is a ____________________.
 

 

 41. 
Fresh water is obtained from salt water through the process of ____________________.
 

 

 42. 
Industries that reduce water use, recycle water, and reuse water are practicing ______________________________.
 

 

 43. 
The addition of any substance to water that has a negative effect on living things is called _________________________.
 

 

 44. 
One source of water pollution is ____________________, which are chemicals used to kill organisms that damage crops.
 

 

 45. 
Some types of water pollution can be cleaned up by ____________________ that consume oil and other toxic chemicals.
 

 

 46. 
An agricultural pollutant that increases the growth of algae in a lake is a ____________________.
 

 

 47. 
Water has ____________________ energy when it is moving.
 

 

 48. 
In a hydroelectric plant, water is stored behind a ____________________ until it is needed to produce electricity.
 

 

 49. 
A dam can destroy wildlife ____________________, places where organisms live.
 

 

 50. 
If too much water is pumped out of an aquifer, the ground above the aquifer may ____________________.
 

 

 51. 
Smoke and exhaust from cars and factories create the form of water pollution called ____________________.
 

 

 52. 
Some people have suggested towing ____________________ from Antarctica to supply fresh water to dry areas of the world.
 

 

 53. 
To kill disease-causing microorganisms, the chemical ____________________ is added to drinking water.
 

 

 54. 
Some people obtain their water from underground layers of rock or sediment called ____________________.
 

 

 55. 
The level of two minerals-calcium and magnesium-in water is referred to as ____________________.
 

 



 
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