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The ACT Science Reasoning Test asks you to answer 40 multiple-choice questions in 35 minutes. The questions test your interpretation, analysis, evaluation, reasoning, and problem-solving skills. The test is made up of seven test units, each of which consists of a passage containing scientific information of the following categories, followed by a number of multiple-choice questions.

  • Biology - cell biology, botany, zoology, microbiology, ecology, genetics, evolution
  • Earth/Space Sciences - geology, meteorology, oceanography, astronomy, environmental sciences
  • Chemistry - atomic theory, inorganic chemical reactions, chemical bonding, reaction rates, solutions, equilibriums, gas laws, electrochemistry, organic chemistry, biochemistry, properties and states of matter
  • Physics - mechanics, energy, thermodynamics, electromagnetism, fluids, solids, light waves
On most Science Reasoning subtests, there are six passages that present scientific data, often based on specific experiments. Also, there's usually one passage in which two scientists state opposing views on the same issue. Each passage will generate between five and seven questions. Some passages will be very hard to understand, but they'll be used to answer many easy questions.

The Science Reasoning directions may look like this:
Directions: Each of the following seven passages is followed by several questions. After reading each passage, decide on the best answer and fill in the corresponding oval on your answer sheet. You are allowed to refer to the passage while answering the questions.

The scientific information presented in each passage is conveyed into one of the three formats:

  • Data Representation requires you to understand, evaluate, and interpret information presented in graphic or tabular form.
  • Research Summaries requires you to comprehend, evaluate, analyze, and interpret the design of an experiment.
  • Conflicting Viewpoints requires you to evaluate two or three alternative theories, hypotheses, or viewpoints on a specific observable phenomenon.
You do not need advanced knowledge in the scientific subjects, but you may need some background knowledge - scientific facts or terms - to answer some of the questions. Most high school students who have completed two years of science coursework will have all the background knowledge they need to successfully understand the passages on the Science Reasoning Test. The passages may test chemistry, biology, botany, physics, or any other science, but you do not have to have had those particular courses. The test gives all the information you need to answer the science questions in the passages or in the diagrams, charts, and tables.

Testing strategies for Science Reasoning Questions are discussed in the later section "ACT Strategies".

If you want to start practicing now, click here to login "ACT Practice" section.