A comprehensive guide on what it takes to get a perfect score on the ACT Science section.
The ACT Science section is a 35-minute, 40-question portion that measures your ability to interpret and analyze scientific information rather than recall facts. It covers biology, chemistry, physics, and Earth/space sciences, but advanced knowledge is not required – only familiarity with basic concepts from introductory high school courses. You cannot use a calculator on this section, but the math required is minimal.
| Type | % of Test | Format | Focus |
|---|---|---|---|
| Data Representation | 25–35% | Graphs, tables, diagrams | Reading charts, identifying trends |
| Research Summaries | 45–60% | Experiment descriptions + results | Understanding experimental design |
| Conflicting Viewpoints | 15–20% | Two+ opposing hypotheses (text only) | Comparing/analyzing viewpoints |
Each passage has about 5–7 questions. Typically you will see 2–3 Data Representation, 2–3 Research Summaries, and 1 Conflicting Viewpoints passage per test. Despite the science context, this section is fundamentally a test of scientific reasoning skills – your ability to interpret data, evaluate experiments, and think logically.
Start by taking a diagnostic ACT Science section to see where you stand. Set a target timeline and break preparation into weeks. Practice ACT Science passages daily if possible (even 15–30 minutes). Each week, take a timed practice section (35 minutes for 40 questions). Focus on weak spots and ramp up closer to the test with full-length ACTs.
After each practice, grade it and review every question. For wrong answers, figure out why. Keep an error log listing the question, the error, and the lesson learned. Identify patterns in your mistakes and do targeted practice on weak areas.
These are filled with graphs, charts, tables, or diagrams. Quickly read titles and labels, identify variables and units, note the data trend, and find answers directly in the figures. For interpolation/extrapolation questions, use the trend to estimate.
These describe experimental setups and findings. Identify the research question, independent variable, dependent variable, control group, and constants. Understand the results and apply scientific reasoning to answer questions about experimental design and conclusions.
These present two or more opposing hypotheses with no data graphs – purely textual. Identify each viewpoint's main claim and evidence. Look for key differences and similarities. Questions frequently ask how viewpoints differ or what they might agree on.
Typically 3-4 questions per test require basic scientific knowledge not provided in the passages:
| Subject | Key Concepts |
|---|---|
| Biology | Cell organelles, DNA/RNA, photosynthesis/respiration, natural selection, food chains |
| Chemistry | pH scale (7 neutral), states of matter, phase changes, atoms/molecules, catalysts |
| Physics | Newton's laws, gravity (9.8 m/s²), density = mass/volume, kinetic vs potential energy, waves |
| Earth/Space | Earth layers, plate tectonics, water cycle, greenhouse effect, rock types |
Key formulas: F = ma, Density = mass/volume, Speed = distance/time, V = IR (Ohm's Law), PV = nRT (Ideal Gas Law).
For any experiment, identify the independent variable (changed), dependent variable (measured), controls (kept constant), and control group (baseline). Understand the experimental purpose, check procedures for limitations, summarize results, and draw conclusions tied to the data.
If a question changes a condition or adds a new scenario, extrapolate from the existing trend. Remember that correlation does not equal causation – experiments without proper controls cannot definitively prove cause-effect.
Use the passage as your truth source. Eliminate answers that contradict the data, introduce irrelevant concepts, misquote values, or use unsupported extreme language. When stuck between two choices, check the data carefully.
Skim passages strategically – do not read every word. Mark up figures and text. Let questions direct you to details. Use line and figure references. Keep moving if stuck. Be especially careful with "NOT" or "EXCEPT" questions.