Ged Science Practice Test 4 - online test

Which of the following energy sources causes the least pollution to the environment?


nuclear power




There is no pollution or waste associated with solar energy.

It is generally known that a compass needle will point north. It does not point to the geographical North Pole, but to the magnetic north pole. The Chinese tell stories of their seagoing ancestors whose compasses pointed south. For a long time, no one believed these stories. Then scientists discovered that periodically the magnetic poles of Earth reverse themselves.
What assumption made scientists unwilling to believe the stories about the ancient Chinese sailors?

Compasses are a very old invention.

Magnets have two poles: a north pole and a south pole.

Local iron deposits in the earth can affect the direction in which the compass needle points.

Earth's magnetic poles cannot change.

Compasses always line up with Earth's north and south poles.

Until researchers discovered that Earth's magnetic poles could reverse themselves, there was no reasonable explanation for compasses pointing south.

Homeostasis is a state of equilibrium. Every living thing tries to achieve homeostasis by regulating its processes.
To achieve homeostasis, a cell that has taken in food would also need to do which of the following?

use less energy

take in still more food

stop all other functions

release waste materials

divide into two cells

A cell that has taken in food seeks balance by releasing wastes.

Camels, like all animals, need water to live. Yet they are able to go up to ten days without eating or drinking. Many people believe that camels store water in their humps, but others disagree.
Which of the following statements would help prove that water is NOT stored in a camel's hump?

The hump becomes smaller when there is nothing to eat or drink.

The hump gets smaller when there is no food but water is available.

A camel can live for months on green grass and no water.

A camel's hump may contain up to fifty pounds of fat.

The hump becomes larger when the camel eats and drinks.

This choice indicates that the lack of food causes the hump to shrink. If water is available but food is not and the hump gets smaller, the hump must contain an energy source.
Scientists performed an experiment to determine whether there is a connection between learning ability and food. They took two groups of 20 mice each, all from the same purebred strain. The mice were deprived of food for 3 days and then given a standard learning session in running through a maze. They were trained by giving them a mild electric shock whenever they took a wrong turn. Immediately after each learning session, one group of mice was fed, but the other was not, A week later, all of the mice were tested to see whether they could still run the maze correctly. The group that had been fed had retained this ability, but the other group had not.

The probable reason that the scientists used only mice from the same pure-bred strain is so that

the mice would all be the same size

the mice would all be the same color

the experiment could be repeated with the same mice

genetic differences would not affect the outcome of the test

the experiment wouldn't cost as much

Neither size nor color was a factor in this experiment, nor was the cost an issue. The same mice could not be reused: the variable in this experiment is learning, and the mice had already been influenced.

A finding is a proven result obtained as part of an experiment.
Which of the following could be considered a valid finding?

Mice remember better if they are fed immediately after each training session.

Mice remember better if they are fed and then allowed some time to think about the training.

Experiments with mice have nothing to do with human learning processes.

Mice used in experiments have to be from the same purebred strain.

Mice do not need to be fed in order to learn.

This choice is a conclusion that can he drawn from the experiment. All the other choices are irrelevant or erroneous.

The use of an electric shock in the teaching process is

necessary to keep the mice alert

cruel and should not be allowed

a way to show the mice that they have taken a wrong turn in the maze

designed to elicit a predetermined response

part of the variable

This answer is given in the passage.

It was noted that the mice could learn to run the maze more readily if it was well illuminated.
This information is

not relevant to their experiment

vital to the experiment

an assumption made by someone who observed the experiment

a result of the experiment

an important finding

The issue of illumination was not part of the experiment and therefore irrelevant.
Acid rain, more properly known as acid precipitation, is a man-made environmental problem that is known to be escalating. The source of acid rain is oxides of sulfur and nitrogen that dissolve in water, lowering the pH to such an extreme that damage to living and nonliving things results. Often the source of acid rain is pollutants from factories or automobiles. The gases produced by fuel combustion react with water vapor in the air and produce acids such as sulfurous acid, sulfuric acid, and nitrous acid. Burning of coal, oil, and natural gas is especially likely to cause an increased amount of acid rain. In addition to man-caused sources of acid rain, volcanic eruptions and some bacterial decay also produce these acidic oxides which lower the pH of water.

Scientists measure the acidity of an object using the pH scale. The scale ranges from 0 to 14, with a pH of 7 being considered neutral. A pH less than 7 is acidic and one more than 7 is basic or alkaline. Normal rain has a pH of about 5.6. It is not neutral because rainwater naturally dissolves a small amount of carbon dioxide from the air and becomes slightly acidic.

Acid rain becomes a serious problem when the pH of the precipitation becomes less than 3.5. There have been reported pH of 1.3 in some areas. These extremely acidic conditions kill fish and plants, and may render lakes and soil totally uninhabitable. Young fish not only are killed by such acidic waters, but any fish that may survive are usually not able to reproduce. Sometimes, nature provides a means of neutralizing these acidic waters via naturally alkaline ammonia compounds or calcium compounds such as limestone,

The list below gives the pH of some common substances:
1.1: Battery acid
2.8: Household vinegar
5.5: Normal rainwater
7.0: Distilled water
8.2: Baking soda
11.6: Household ammonia
13.9: Lye

Which of the following mineral formations would be most effective at neutralizing acid rain?



calcium carbonate

magnesium acetate

baking soda

The passage specifically mentions calcium compounds as being natural neutralizers of acid rain.

Which of the following is not a cause of acid precipitation?

automobile engines

gasoline-powered lawnmowers

burning of coal

hydroelectric plants

burning of natural gas

Hydroelectric plants do not burn fossil fuels to generate electricity. All of the other choices are specifically mentioned as contributing to acid rain.

According to the passage, which of the following is the most basic?



distilled water

normal rainwater

battery acid

The chart shows that the highest pH substance listed is lye, the most basic. The information is almost always provided to you. Your job is to take the information given in the passage and use it to answer the questions.

Which pair of substances would likely neutralize each other?

lye and ammonia

vinegar and battery acid

vinegar and ammonia

ammonia and calcium carbonate

distilled water and rainwater

Neutralization requires an acid and a base. The only combination listed among the choices that has an acid and a base is vinegar and ammonia.

Which of the following responses to an acid rain-caused fish kill would have the best chance of preventing the problem from reappearing?

restocking the lake with heartier fish

allowing the stronger fish to survive and then reproduce

seeding clouds so that the rain falls elsewhere

reducing the amount of air pollution created

adding large amounts of ammonia to the lake to neutralize the acid

The best approach would be to reduce or stop the problem at its source. The other choices would do nothing to prevent the same problems from reappearing again.

Which of the following compounds does not dissolve in water and cause acid rain?

sulfur dioxide

sulfur trioxde

carbon dioxide

nitrogen dioxide

nitrogen monoxide

The passage specifically mentions that carbon dioxide dissolving in water does not cause acid rain. It also tells you that oxides of nitrogen and sulfur are leading causes of acid rain.

Chemical fertilizers stimulate plant growth; but if the concentration is too high, they may damage roots.
What precautions concerning chemical fertilizers must a gardener take?

Use them only on some of his or her plants

Use only the amount recommended.

Do not apply chemical fertilizers.

Apply as much as possible without damaging roots.

Give the plants only tiny amounts.

The only way the gardener can know how much to use is to follow the instructions given.

Amniote vertebrates are generally classified into three orders: Reptilia, Ayes (birds), and Mammalia.
Of the following, which group of three animals contains one member of each order?

ostrich, American robin, Norway rat

Beluga whale, black-footed ferret, box turtle

timber rattlesnake, fence lizard, leopard

African lion, sea otter, herring gull

house sparrow, garter snake, African elephant

Reptilia: garter snake
Aves: house sparrow: 
Mammalia: African elephant.
Ions are electrically charged particles that are formed when certain compounds are dissolved in water. These solutions will conduct electricity. The Swedish scientist Svante Arrhenius coined the term ion (which means wanderer) to explain why solutions of electrolytes will conduct an electric current. When an electrolyte forms into a solution, it dissolves or dissociates into ions, a process called ionization. If a substance does not ionize, it will not conduct an electric current.

Electrolytes include most acids, bases, and salts. Some conductors include hydrogen and sodium chloride, copper sulfate, and potassium nitrate. Substances that are not electrolytes include distilled water, sugar water, and most organic compounds.

Which of the following is a nonelectrolyte?

HNO3 (nitric acid)

HCl (hydrochloric acid)

H2SO4 (sulfuric acid)

C3H8 (propane gas)

NaCl (table salt)

Propane (C3H8) is an organic compound. HNO3, H2SO4 and HCL are acids. NaCl is a salt.

Which of the following compounds in the liquid phase can be considered an electrolyte?

H2O (distilled water)

CO2 (carbon dioxide)

NaCl (sodium chloride)

CuO (oxidized copper)

H2O2 (hydrogen peroxide)

The only solution among the answers that is specifically identified in the passage as an electrolyte is sodium chloride.

An object accelerates (changes its speed) only if the forces acting on it in one direction are greater than the forces in the opposite direction, All of the following objects will accelerate EXCEPT

a gas balloon in which the buoyant force is greater than its weight and air resistance

a man in a parachute when the air resistance is less than his weight

an airplane in horizontal flight when the thrust of the engine is equal to the drag of the air

a ball striking a wall, in which the force of the ball on the wall is equal to the force of the wall on the ball

a rocket fired straight up, when the engine thrust is equal to the air resistance

In horizontal flight, the engine thrust pushes the plane forward and air drag holds it back: If they are equal. there will be no change in speed.
Humidity is the amount of water vapor in the air at a given time. At warm temperatures, air can hold more moisture than it can at cold temperatures. Relative humidity is the amount of vapor the air is holding expressed as a percentage of the amount the air is capable of holding. For example, at 86 degrees Fahrenheit, air can hold a maximum of 30.4 grams of water per cubic meter. If the air at the same temperature is holding only 15.2 grams of water, the relative humidity is 50 percent. At the point at which the air becomes saturated (exceeds the level of water vapor it can hold), it releases water vapor in the form of dew or condensation.

If the air at 75 degrees's holding the maximum amount of moisture that it can, and the temperature suddenly drops to 60 degrees, what is likely to be the result?

The humidity will remain unchanged.

The relative humidity will decrease.

Precipitation will be released in the form of rain.

Precipitation will be released in the form of hail.

Precipitation will be released in the form of snow.

According to the passage, warm air holds more moisture than cold air; therefore, when the temperature drops, the cold air cannot hold the amount of moisture that the warmer air held. At that temperature, the sturation point would be exceeded and the excess humidity would be released as rain.