Science Practice for the ACT
The ACT Science section is 40 multiple-choice questions in 35 minutes, distributed across six or seven passages. The passages come in three formats: Data Representation (graphs and tables), Research Summaries (described experiments), and Conflicting Viewpoints (two or three competing scientific opinions). The section tests data interpretation and scientific reasoning — outside content knowledge is rarely required.
Subtopic drills
The Science section breaks down into 6 recurring question types. Click any subtopic to see graded drill sets.
Data Representation
Reading graphs and tables; trends, interpolation, extrapolation, units.
Research Summaries
Two or three related experiments with shared variables — design and inference questions.
Conflicting Viewpoints
Two or three scientists or hypotheses presented for compare-and-contrast questions.
Biology
Cells, ecology, evolution, physiology — interpreted from passage data, not memorized.
Chemistry
Reactions, solutions, equilibrium, periodic trends — passage-driven.
Physics
Motion, forces, energy, waves, electricity — read off the graph, then answer.
How the Science section is scored
Your raw score (number correct out of 40) converts to a 1–36 scaled score. Science has historically had a forgiving curve at the top — a 38/40 raw still often scores a 33 — and a steep curve in the middle.
Strategy notes
Read the passages in the order they are easiest for you, not in printed order. Save Conflicting Viewpoints for last (or first, if you are strong at it) — it is the only passage type that requires you to actually read prose.
Skip the introductory paragraph on Data Representation passages. Go straight to the figure, read the axes, then read the questions. You can come back to the intro if you need it; usually you do not.
Treat the figures as if they are math problems. ACT Science is not chemistry or biology trivia — it is reading graphs and tables under time pressure. If you can read a stock chart, you have most of the skills you need.
Common mistakes
- Letting unfamiliar vocabulary throw you off. The ACT defines anything unusual either in the passage or in a footnote; you do not need to know what "thermophilic" means before you walk in.
- Picking trend answers based on the wrong axis. Always read both axis labels and units before answering.
- Spending too long reading Conflicting Viewpoints. Skim, then go to the questions; the questions will tell you what details to re-read.
- Forgetting that "according to Scientist 2" requires you to ignore Scientist 1's data, even if you think Scientist 1 is right.
What to drill first
Start with Data Representation drills — they are the easiest format and the largest share of points. Then move to Research Summaries. Save Conflicting Viewpoints for last unless reading is your strongest section.
Recommended Reading
- Official ACT Science outlineact.org
- Top study mistakes for ACT Scienceprepscholar.com