Best GED Science Practice Questions

Think you’re ready for the GED Science subject test? Test your knowledge with these GED science practice questions to give yourself an idea of how you might do on test day. Answers are at the end of the post.

If, at the end of this, you find you might need a little more studying, check out these other helpful science posts:

GED Science Practice Questions

Questions 1-3 are based on the following passage, adapted from a biography of scientist John Dalton from the U.S. Energy Information Administration.

John Dalton was born in England in 1766, ten years before the U.S. Declaration of Independence was signed. His family lived in a small thatched cottage. As a small child, John worked in the fields with his older brother, and helped his father in the shop where they wove cloth. Although they had enough to eat, they were poor. Most poor boys at that time received no education, but John was lucky to attend a nearby school. In 1766, only about one out of every 200 people could read.

John was a good student and loved learning. His teachers encouraged him to study many things. John studied the weather and the nature around him. He collected butterflies, snails, mites, and maggots. He measured his intake of food and compared it to his production of waste. He discovered he was color-blind and studied that, too.

In 1793, John moved to Manchester as a tutor at New College and began observing the behavior of gases. He began to think about different elements and how they are made. He had a theory that each element is made up of identical atoms and that all elements are different because they are each made of different atoms. He thought that each element had a different weight, because it was made of different atoms.

In 1808, Dalton published a book, A New System of Chemical Philosophy, which listed the atomic weights of many known elements. His weights were not all accurate, but they formed the basis for the modern periodic table. Not everyone accepted Dalton’s theory of atomic structure at the time, however. He had to defend his theory with more research.

When John Dalton died in 1844, he was buried with honors in England. More than 400,000 people viewed his body as it lay in state. As his final experiment, he asked that an autopsy be performed to find out the cause of his color-blindness. He proved that it was not caused by a problem with his eyes, but with his perception-the way his brain worked. Even in death, he helped expand scientific knowledge.

Today, scientists everywhere accept Dalton’s theory of atomic structure. A simple country boy showed the world a new way of thinking about the universe and how it is made.

1. Which of the following was a hypothesis posited by John Dalton?

A) The modern periodic table does not include all elements that must exist.
B) A structural problem in his eyes caused color-blindness.
C) Elements are unique in their atomic composition.
D) Gases are made up of different elements.

2. Which of these was not an area of scientific study for Dalton, according to the passage?

A) Biology
B) Chemistry
C) Earth Science
D) Physics

3. In the second paragraph, the author mentions that John Dalton studied which of his own body systems?

A) Respiratory
B) Digestive
C) Skeletal
D) Endocrine

Questions 4-5 are based on the following information from the U.S. Energy Information Administration.

When people use electricity in their homes, the electrical power was probably generated by burning coal, by a nuclear reaction, or by a hydroelectric plant on a river, to name just a few sources. Therefore, coal, nuclear, and hydro are called energy sources. When people fill up a gas tank, the source might be petroleum refined from crude oil or ethanol made by growing and processing corn.

Energy sources are divided into two groups:

  • Renewable (an energy source that can be easily replenished)
  • Nonrenewable (an energy source that cannot be easily replenished)

Renewable and nonrenewable energy sources can be used as primary energy sources to produce useful energy such as heat or used to produce secondary energy sources such as electricity.

4. Label each of the following as either a renewable or non-renewable energy source:
Coal: ________
Solar power: _________
Hydropower: ________
Petroleum: _________
Ethanol: ___________

5. According to the passage, ethanol is used to

A) heat homes.
B) fuel automobiles.
C) process corn.
D) provide electricity.

Questions 6-8 are based on the following information and diagram from the U.S. Geological Survey.

The cohesive forces between liquid molecules are responsible for the phenomenon known as surface tension. The molecules at the surface of a glass of water do not have other water molecules on all sides of them and consequently they cohere more strongly to those directly associated with them (in this case, next to and below them, but not above). It is not really true that a “skin” forms on the water surface; the stronger cohesion between the water molecules as opposed to the attraction of the water molecules to the air makes it more difficult to move an object through the surface than to move it when it is completely submersed.

The cohesive forces between molecules in a liquid are shared with all neighboring molecules. Those on the surface have no neighboring molecules above and, thus, exhibit stronger attractive forces upon their nearest neighbors on and below the surface. Surface tension could be defined as the property of the surface of a liquid that allows it to resist an external force, due to the cohesive nature of the water molecules.

GED Science Practice Questions: Surface Tension- Magoosh

Water molecules want to cling to each other. At the surface, however, there are fewer water molecules to cling to since there is air above (thus, no water molecules). This results in a stronger bond between those molecules that actually do come in contact with one another, and a layer of strongly bonded water (see diagram). This surface layer (held together by surface tension) creates a considerable barrier between the atmosphere and the water. In fact, other than mercury, water has the greatest surface tension of any liquid.

6. Which of these examples best illustrates surface tension?

A) Some objects are able to float in water.
B) Some small insects can walk on top of water.
C) Ice is less dense than liquid water.
D) Water is able to erode rocks and other surfaces.

7. Which of the following has the highest level of surface tension?

A) Water
B) Alcohol
C) Gasoline
D) Mercury

8. The water molecules below the surface

A) form equal bonds with all of the other water molecules they contact.
B) form stronger bonds with those molecules next to them than with those below them.
C) are unable to form bonds with water molecules on the surface.
D) are smaller than water molecules on the surface.

Answer Key

1. C
The third paragraph states, “He had a theory that each element is made up of identical atoms and that all elements are different because they are each made of different atoms.” Each element is unique because of its atomic composition.

2. D
Physics is not among the areas that the passage mentions as an area of study for John Dalton. The passage does say that he studied biology (the study of life) because he studied various organisms and their body processes. It also says that he studied chemistry, evidenced by his work relating to atoms and elements. The passage also mentions that he studied the weather, which is a component of Earth Science.

3. B
The passage states that Dalton “measured his intake of food and compared it to his production of waste.” This relates to the digestive system, which is responsible for the way the body consumes and processes food.

4. non-renewable; renewable; renewable; non-renewable; renewable
Coal is a rock made mostly from carbon. It is considered non-renewable since it takes millions of years to form. Solar power is a renewable energy source because we constantly receive heat and light energy from the sun. Hydropower is a renewable resource because of the Earth’s vast supply of water, which remains in place due to the water cycle. Petroleum is made from crude oil, which is a non-renewable resource that takes millions of years to form. As the passage describes, ethanol is made from corn, which is a renewable resource because more can easily be grown.

5. B
The passage mentions ethanol as one energy source that people use to “fill up a gas tank,” which means that it is used as an automotive fuel.

6. B
The passage states, “Surface tension could be defined as the property of the surface of a liquid that allows it to resist an external force, due to the cohesive nature of the water molecules.” Surface tension is what would allow a small insect such as a water strider to walk on the surface of the water. The water molecules on the water’s surface are so tightly bound to one another that the insect’s light weight is not enough to break through the surface, allowing the insect to walk on water.

7. D
The passage states that water has the greatest surface tension of any liquid other than mercury, which means that mercury’s surface tension is the highest.

8. A
The diagram shows that water molecules below the surface bond equally with the other water molecules on all sides of them. It is only the surface molecules that form uneven bonds, bonding more strongly with one another than with the molecules below them.


  • Sarah Bradstreet

    Sarah is an educator and writer with a Master’s degree in education from Syracuse University who has helped students succeed on standardized tests since 2008. She loves reading, theater, and chasing around her two kids.