Understanding Scientific Concepts Quiz

Which of the following best defines a scientific law?

• A detailed explanation of why phenomena occur

• A statement that describes a consistent relationship observed in nature

• A guess based on personal opinion

• An experiment that tests a hypothesis

Answer explanation

A scientific law is best defined as a statement that describes a consistent relationship observed in nature, distinguishing it from theories, guesses, or experiments.

What is an independent variable in a scientific experiment?

• The variable that is measured

• The variable that is kept constant

• The variable that is changed by the experimenter

• The result of the experiment

Answer explanation

The independent variable is the one that the experimenter changes to observe its effect on the dependent variable. It is crucial for testing hypotheses and determining cause-and-effect relationships.

Tags

NGSS.MS-PS2-2

Which of the following is a controlled variable?

• The variable that is measured

• The variable that is changed

• The variable that is kept the same throughout the experiment

• The variable that is not used

Answer explanation

A controlled variable is the one that is kept the same throughout the experiment to ensure that the results are due to the changes in the independent variable. This helps maintain the integrity of the experiment.

Tags

NGSS.MS-PS3-4

What is the main purpose of the scientific method?

• To memorize facts

• To organize and conduct investigations to answer questions

• To prove all theories correct

• To create new laws

Answer explanation

The main purpose of the scientific method is to organize and conduct investigations to answer questions. It emphasizes systematic inquiry rather than merely memorizing facts or proving theories.

Tags

NGSS.MS-PS2-2

Which of the following is an example of an observation?

• The plant grew 5 cm in one week

• The plant will grow faster if it gets more sunlight

• The plant looks healthy because it is green

• The plant is probably thirsty

Answer explanation

The correct choice, 'The plant grew 5 cm in one week', is a direct measurement and factual statement, making it an observation. The other options are interpretations or predictions, not observations.

A theory in science is best described as:

• A guess with no evidence

• A well-supported explanation based on evidence

• A law that has been proven

• A single observation

Answer explanation

A theory in science is a well-supported explanation based on evidence, distinguishing it from mere guesses or single observations. It is not a law, which is a statement of fact that has been proven under specific conditions.

Tags

NGSS.HS-LS4-2

Which variable is the dependent variable in an experiment where you test how the amount of sunlight affects plant growth?

• Amount of sunlight

• Type of plant

• Amount of water

• Plant growth

Answer explanation

In this experiment, plant growth is the dependent variable because it is the outcome being measured. The amount of sunlight is the independent variable that is being manipulated to observe its effect on plant growth.

Tags

NGSS.MS-LS1-5

NGSS.MS-LS2-1

Which step comes first in the scientific method?

• Forming a hypothesis

• Making observations

• Drawing conclusions

• Analyzing data

Answer explanation

The first step in the scientific method is making observations. This involves gathering information and noticing phenomena, which leads to questions and the formation of a hypothesis.

Which of the following statements is an inference?

• The sky is cloudy

• It is going to rain soon

• The temperature is 20°C

• The wind is blowing

Answer explanation

The statement 'It is going to rain soon' is an inference based on the observation that 'The sky is cloudy.' The other statements are direct observations, not inferences.

Tags

NGSS.MS-ESS2-5

Which of the following best distinguishes a theory from a law?

• A law explains why things happen, a theory describes what happens

• A theory is a guess, a law is proven

• A theory explains why things happen, a law describes what happens

• Both are the same

Answer explanation

The correct choice is that a theory explains why things happen, while a law describes what happens. Laws are statements based on repeated observations, whereas theories provide the underlying reasons for those observations.