Scientific Experiments and Variables Worksheet

A student places bean plants in four different rooms with varying amounts of light: no light, low light, medium light, and bright light. After three weeks, she measures the average plant height in each room. Which conclusion is best supported by this setup?

• The independent variable is the plant height, and the dependent variable is the light level.

• The independent variable is the amount of light, and the dependent variable is the plant height.

• The dependent variable is the amount of water given, and the independent variable is the amount of light.

• The experiment cannot show a relationship between light and plant growth.

Tags

NGSS.MS-LS2-1

NGSS.MS-LS1-5

NGSS.MS-LS2-4

A teacher gives two groups of students different types of pencils (mechanical vs. wooden) and asks them to write an essay. She then measures the number of words each student writes.

Which of the following is the dependent variable in this experiment?

• The number of words in the essay.

• The type of pencil used.

• The grade level of the students.

• The length of time students were given.

A biologist tests the effect of fertilizer on tomato growth. She grows 20 plants with fertilizer and 20 without. She then measures the height of each plant after six weeks.

Which of the following would make the experiment more reliable?

• Record only the tallest tomato plants in each group.

• Repeat the experiment multiple times with new plants.

• Test only one plant with fertilizer and one without.

• Change the fertilizer type halfway through the experiment.

Tags

NGSS.MS-LS2-1

NGSS.MS-LS1-5

Students conducted a survey about favorite ice cream flavors. Out of 100 students, 40 chose chocolate, 35 chose vanilla, 20 chose strawberry, and 5 chose other flavors. Which conclusion is supported by these results?

• More students prefer vanilla than strawberry.

• Strawberry is the most popular flavor.

• Chocolate and vanilla are equally popular.

• Other flavors are as popular as chocolate.

A scientist states the following hypothesis: “Saltwater freezes at a lower temperature than freshwater.” She places equal amounts of freshwater and saltwater into a freezer and records the temperature at which each freezes.

What is the dependent variable in this experiment?

• The freezing temperature of the water.

• The amount of water in each container.

• Whether the water is saltwater or freshwater.

• The temperature of the freezer.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

A student repeats an experiment three times to measure how quickly sugar dissolves in hot water vs. cold water. Why is repeating the experiment important?

• To prove that the hypothesis is correct.

• To ensure the results are consistent and reliable.

• To change the outcome of the experiment.

• To reduce the amount of data collected.

The graph below shows the number of hours teenagers spend on homework each week compared to their test scores. Based on the graph, what is the relationship between hours spent on homework and test scores?

• Teenagers who spend more hours on homework tend to have higher test scores.

• Teenagers who spend fewer hours on homework tend to have higher test scores.

• There is no relationship between hours spent on homework and test scores.

• Teenagers who spend more hours on homework tend to have lower test scores.

Which conclusion is best supported?

• More time on homework tends to be related to higher test scores.

• Students who do more homework always earn perfect scores.

• Homework causes students to learn less.

• There is no relationship between homework and scores.

A group of scientists found that greenhouse gases trap heat in Earth’s atmosphere. Later experiments confirmed the same conclusion. What does this example show about science?

• A. Scientific knowledge can change when new evidence is found.

• B. Once an idea is published, it cannot be questioned.

• C. Scientific results do not need to be tested more than once.

• D. Science is based only on opinions and beliefs.

A chemistry student places metal strips in different liquids to test how quickly they corrode. She records the time it takes for visible rust to appear. Which is the dependent variable in this experiment?

• The type of metal strip used.

• The type of liquid used.

• The time until rust appears.

• The size of the metal strip.

Tags

NGSS.MS-PS1-2