PreACT Science practice: passages, questions and explanations

The PreACT has a Science section only if your school or district gives it: Science is optional on every PreACT version as of fall 2026, and it no longer counts toward the Composite. When it's given, PreACT and PreACT Secure Science has 36 questions in 40 minutes; PreACT 9 Secure Science has 32 questions in 35 minutes.

Below are 18 free practice questions on three original passages, one of each kind ACT uses: a data passage with a table and a graph, a two-experiment study, and two students who disagree. Each answer comes with an explanation, and your results show which skill to practice next. We wrote every passage ourselves; the test facts come from ACT on act.org, checked November 11, 2026.

PreACT Science practice passages and questions

Work the passages in order, the way the real section mixes them. At the PreACT pace of about 67 seconds per question, these 18 questions should take about 20:00 minutes, reading included. Start the clock if you want a pacing check; leave it off to practice untimed first.

PreACT Science practice: 3 passages, 18 questions

Choose an answer to see the explanation. No calculator, as on the real test. To check your pace, start the clock before you read Passage I.

Pace me against:

Target for all 18 questions at PreACT and PreACT Secure pace: about 20:00 (minutes:seconds).

Data Representation · Questions 1 to 6

Passage I: A shaded stream

Students sampled a small stream at five sites, starting under a forest (Site 1) and moving downstream past fields where fewer trees shade the water. At each site they estimated shade cover, measured water temperature and dissolved oxygen (the oxygen gas dissolved in the water, which aquatic insects need), and counted mayfly nymphs in a kick-net sample of the same size.

Table 1 shows the site measurements. Figure 1 shows the mayfly counts. All data are from one afternoon in early summer.

Table 1
Site	Distance downstream (km)	Shade cover (%)	Water temperature (°C)	Dissolved oxygen (mg/L)
1	0	80	12	10.4
2	2	60	14	9.8
3	4	30	17	9
4	6	10	20	8.2
5	8	10	21	7.9

Figure 1

1. According to Table 1, what was the water temperature at the site with 30% shade cover? (Reading tables and graphs)

Show answer and explanation

Answer: (B). Find 30% in the shade cover column: that's Site 3. Read across to water temperature: 17°C. Choice D is Site 3's dissolved oxygen (9.0 mg/L) with the wrong unit, a classic wrong-column trap.

2. According to Table 1, as distance downstream increased, water temperature and dissolved oxygen changed in which way? (Trends and interpolation)

Show answer and explanation

Answer: (D). From Site 1 (0 km) to Site 5 (8 km), temperature rises at every step (12, 14, 17, 20, 21°C) while dissolved oxygen falls at every step (10.4, 9.8, 9.0, 8.2, 7.9 mg/L). The two variables move in opposite directions.

3. Based on Table 1, if the students had also measured water temperature 5 km downstream, the temperature would most likely have been: (Trends and interpolation)

Show answer and explanation

Answer: (B). 5 km is between Site 3 (4 km, 17°C) and Site 4 (6 km, 20°C). Temperature rises steadily downstream, so the value at 5 km should fall between those two readings, about 18 to 19°C.

4. Based on Table 1 and Figure 1, how many mayfly nymphs were counted per sample at the site where dissolved oxygen was 8.2 mg/L? (Reading tables and graphs)

Show answer and explanation

Answer: (C). Table 1 shows 8.2 mg/L at Site 4. In Figure 1, the bar for Site 4 is at 9. Choice A is Site 5's count; it's the right figure but the wrong bar.

5. Which statement about the five sites is best supported by Table 1 and Figure 1? (Trends and interpolation)

Show answer and explanation

Answer: (A). Ranked by dissolved oxygen (10.4, 9.8, 9.0, 8.2, 7.9), the counts are 42, 35, 21, 9 and 6: more oxygen goes with more nymphs at every site. C is false (Sites 4 and 5 both have 10% shade but counts of 9 and 6), and D is backward. The data show an association, not proof that oxygen causes the difference.

6. A student claims that the number of mayfly nymphs at a site depends only on shade cover. Which two sites provide the best evidence against this claim? (Experimental design and controls)

Show answer and explanation

Answer: (D). If shade were the only factor, two sites with the same shade would have the same count. Sites 4 and 5 both have 10% shade cover but different counts (9 and 6). Every other pair differs in shade, so its difference in count fits the claim.

Research Summaries · Questions 7 to 12

Passage II: Salt and seed germination

Road salt (sodium chloride, NaCl) can wash into soil near roads. A student studied how salt affects the germination (sprouting) of radish seeds.

Experiment 1: The student placed 50 radish seeds on a paper towel in each of 5 dishes and wet each towel with 10 mL of an NaCl solution. The solutions had concentrations of 0, 2, 4, 6 and 8 grams of NaCl per liter of water (g/L). All dishes were covered and kept in the dark at 22°C. After 5 days, the student counted the seeds that had germinated (Table 2).

Experiment 2: The student repeated Experiment 1 using only the 0 g/L and 4 g/L solutions, with dishes kept at 12°C, 17°C, 22°C or 27°C. Each dish again held 50 seeds and 10 mL of solution, and germinated seeds were counted after 5 days (Table 3).

Table 2 (Experiment 1, 22°C)
NaCl concentration (g/L)	Seeds germinated (of 50)
0	46
2	44
4	35
6	19
8	7

Table 3 (Experiment 2): seeds germinated (of 50)
Temperature (°C)	0 g/L NaCl	4 g/L NaCl
12	30	14
17	41	26
22	46	35
27	45	37

7. In Experiment 1, which dish served as the control? (Experimental design and controls)

Show answer and explanation

Answer: (D). The control is the dish without the factor being tested. The 0 g/L dish got plain water, so it shows how many seeds germinate with no salt, the baseline the salty dishes are compared to.

8. In Experiment 1, what percent of the seeds in the 6 g/L dish germinated? (Reading tables and graphs)

Show answer and explanation

Answer: (B). 19 of 50 seeds germinated. 19 ÷ 50 = 0.38, or 38%. Choice A uses the count as if it were a percent; choice C is the percent that did not germinate. No calculator is allowed on PreACT Science, so practice quick conversions like dividing by 50 (double it, then read it as a percent).

9. If Experiment 1 had included a dish with 5 g/L NaCl, the number of seeds germinated in that dish would most likely have been: (Trends and interpolation)

Show answer and explanation

Answer: (C). 5 g/L is between 4 g/L (35 seeds) and 6 g/L (19 seeds), and germination falls as concentration rises. So the count should land between 19 and 35. Choice B is the range between 6 and 8 g/L.

10. How did Experiment 2 differ from Experiment 1? (Experimental design and controls)

Show answer and explanation

Answer: (A). Experiment 2 used the same seeds, the same 10 mL of solution and the same 5-day count, but tested four temperatures with just the 0 and 4 g/L solutions. Nothing in the passage says the seeds, light or volume changed.

11. In Experiment 2, as temperature increased from 12°C to 27°C, the difference between the number of seeds germinated at 0 g/L and at 4 g/L: (Trends and interpolation)

Show answer and explanation

Answer: (B). Subtract across each row of Table 3: 30 − 14 = 16, 41 − 26 = 15, 46 − 35 = 11 and 45 − 37 = 8. The gap shrinks at every step, so it decreased only. Don't confuse this with the 0 g/L column alone, which rises and then dips slightly.

12. The student wants to find out whether salt affects lettuce seeds the same way it affects radish seeds. Which new experiment would best test this? (Experimental design and controls)

Show answer and explanation

Answer: (C). To compare seed types, change only the seed type and keep every other condition the same as Experiment 1. Then any difference in the results can be traced to the seeds. The other choices don't include lettuce at all.

Conflicting Viewpoints · Questions 13 to 18

Passage III: Why does metal feel colder?

A metal spoon and a wooden spoon have been lying on a table in a room kept at 20°C for several hours. A student picks up one spoon in each hand. The metal spoon feels much colder than the wooden spoon. Two students explain why.

Student 1

The metal spoon really is colder than the wooden spoon. Metals take in cold from their surroundings and hold on to it, so a metal object stays below room temperature even after hours in the room. Wood does not hold cold this way, so the wooden spoon is at room temperature. Your hand feels the metal spoon as colder because its temperature is lower.

Student 2

After several hours in the room, both spoons are at the same temperature as the room, 20°C. A hand is warmer than 20°C, so heat flows from the hand into each spoon. Heat always moves from a warmer object to a cooler one, and it moves through metal much faster than through wood. The metal spoon pulls heat out of the skin faster, so the skin touching it cools faster. How cold an object feels depends on how fast it takes heat from your skin, not only on its temperature.

13. Both students would most likely agree that: (Comparing viewpoints)

Show answer and explanation

Answer: (A). Both students accept the observation, that the metal spoon feels colder; they disagree about why. B and D are only Student 2's claims, and C is only Student 1's.

14. According to Student 2, the metal spoon feels colder than the wooden spoon because: (Comparing viewpoints)

Show answer and explanation

Answer: (C). Student 2 says both spoons are at 20°C and that metal pulls heat out of the skin faster than wood. A and B restate Student 1's idea; Student 2 describes heat moving, never cold. Nothing in the passage says wood produces heat.

15. A thermometer is touched to each spoon after both have been in the 20°C room for several hours. It reads 20.0°C for both spoons. This result supports the explanation of: (Comparing viewpoints)

Show answer and explanation

Answer: (B). Student 2 predicts both spoons are at room temperature, which is what the thermometer shows. Student 1 says the metal spoon stays below room temperature, so equal readings contradict Student 1.

16. Student 1's explanation depends on which of the following assumptions? (Comparing viewpoints)

Show answer and explanation

Answer: (D). Student 1 says the metal spoon is still below room temperature after several hours, so the explanation only works if metal can stay colder than its surroundings that long. Student 1 says the wooden spoon is at room temperature (not A), never mentions heat flow (B is Student 2's idea), and C doesn't appear in either view.

17. Both spoons are left in a pot of water at 50°C, which is hotter than skin, until they reach the water's temperature. Based on Student 2's explanation, when the student then holds them, the metal spoon will most likely feel: (Comparing viewpoints)

Show answer and explanation

Answer: (D). Now the spoons are warmer than the hand, so heat flows from the spoons into the skin. Student 2 says heat moves through metal faster, so the metal spoon delivers heat faster and feels hotter. B ignores Student 2's point that feel depends on how fast heat moves, not only on temperature.

18. In the same house, a tile floor feels colder to bare feet than a carpet does. Student 2 would most likely explain this by saying that: (Comparing viewpoints)

Show answer and explanation

Answer: (C). Apply Student 2's rule: objects at room temperature feel colder when they take heat from the skin faster. The tile does that better than the carpet. Choice A is how Student 1 would explain it.

Your results by passage type and skill

Answer questions above and your results appear here, broken down by passage type and skill, with a pacing check and what to practice next.

Last verified against ACT's PreACT FAQ and PreACT Secure and PreACT 9 Secure test guides: November 11, 2026. All passages and questions are original and written by Test Ninjas; the data are made up for practice.

Practice PreACT Science with explanations A free Test Ninjas account gives you PreACT practice with an explanation for every answer, so you can keep working on the skills you missed here.

Create a free account

Is there Science on the PreACT?

Yes, but it's optional, and your school or district decides, not you. ACT made Science optional on the PreACT Secure and PreACT 9 Secure in spring 2026 and on the PreACT and PreACT 8/9 in fall 2026 (PreACT FAQ). ACT's FAQ says the choice is made at the district or school level and not by individual students, so either everyone at your school takes Science or no one does.

Source: ACT, PreACT FAQ, Preparing for PreACT Secure and Preparing for PreACT 9 Secure, checked November 11, 2026. Unscored questions are embedded field-test items, so answer every one as if it counts.

Version	Science questions	Scored	Time	Per question
PreACT and PreACT Secure	36	30	40 min	about 67 sec
PreACT 9 Secure	32	26	35 min	about 66 sec
PreACT 8/9	30	Not yet published	30 min	about 60 sec

When Science is given, it's always the fourth and last test, after English, Math and Reading. ACT allows schools to give a longer break, such as lunch, before Science, or to give Science on a different day in the testing window. For the full test-day schedule, see how long the PreACT is. ACT hasn't released the new PreACT 8/9 blueprint, so its 30-minute timing comes from ACT's current administration manual and may change.

How PreACT Science is scored

Science gets its own score but doesn't count toward the Composite: since fall 2026 (spring 2026 on the PreACT Secure), the PreACT Composite is calculated from English, Math and Reading, the same as on the enhanced ACT (PreACT FAQ). ACT's test guides say Science reports an overall score plus three reporting category scores:

Interpretation of Data: reading tables and graphs, finding trends, interpolating and extrapolating. In our set, that's the "reading tables and graphs" and "trends and interpolation" questions.
Scientific Investigation: how experiments are designed, what is controlled, what was changed and how you'd extend an experiment. Our "experimental design and controls" questions.
Evaluation of Models, Inferences and Experimental Results: judging explanations and whether evidence supports them, which is most of a Conflicting Viewpoints passage. Our "comparing viewpoints" questions.

PreACT scores use a scale that tops out below the ACT's 36: 1 to 35 on the PreACT and PreACT Secure, 1 to 32 on the PreACT 9 Secure and 1 to 30 on the PreACT 8/9, all aligned to the ACT scale (ACT: PreACT scores). There's no penalty for wrong answers; ACT counts only correct answers, so never leave a Science question blank. For how the other scores work, see PreACT scoring explained.

The three PreACT Science passage types

Every PreACT Science passage is one of three formats: Data Representation, Research Summaries or Conflicting Viewpoints (ACT, Preparing for PreACT Secure). Passages cover biology, chemistry, Earth and space science and physics, but ACT says advanced knowledge isn't required. Each format calls for a slightly different approach.

Data Representation

A short introduction followed by tables, graphs or diagrams like those in science textbooks and journals. Questions ask you to find a value, describe a trend, estimate a value between or beyond the data points, or combine two figures. On the PreACT Secure, ACT puts these at about 20 to 35% of the section; on the PreACT 9 Secure the range is higher, about 34 to 63% (Preparing for PreACT 9 Secure), so younger testers see more data and less experiment design.

Tip: skip the introduction on the first pass if the question names a table or figure. Go straight there, read the headings and units, and come back to the text only if a term is unclear. In Passage I, question 4 needs both Table 1 and Figure 1: you find the site in one and the count in the other.

Research Summaries

One or more related experiments, each with its method and results. This is the largest share of PreACT Secure Science, about 50 to 65% (19 to 44% on the PreACT 9 Secure). Questions ask what was changed, what was held constant, what the control was, how two experiments differ, and what a new trial would likely show.

Tip: for each experiment, jot three things in the margin: changed (independent variable), measured (dependent variable) and kept the same (controls). In Passage II, Experiment 1 changes salt concentration, measures germination and keeps temperature, seeds, volume and darkness the same. Experiment 2 changes temperature and tests only two concentrations, which is exactly what question 10 asks.

Conflicting Viewpoints

Two or more scientists or students give different explanations for the same observation. ACT puts these at about 20 to 35% of PreACT Secure Science (19 to 44% on the PreACT 9 Secure). Questions ask what each one claims, where they agree, which evidence supports or weakens a view, and what a view predicts in a new situation. These passages usually have the most reading per question.

Tip: before the questions, write a one-line summary of each view and what it predicts. In Passage III: Student 1, metal is really colder; Student 2, same temperature, metal moves heat faster. Then a question like "a thermometer reads 20.0°C for both" sorts itself in seconds. Answer from the viewpoint, not from what you know to be true; question 17 asks what Student 2 would predict, not what's correct.

How to read PreACT Science tables and graphs fast

Read the labels before the numbers, find the one row or line the question needs, and say the trend in words before you look at the choices. Most data questions take well under the average time if you follow the same routine each time:

Title, axes, units. Know what each column or axis measures and in what unit: °C, mg/L, a count, a percent. Many wrong choices are the right number from the wrong column, like "9.0°C" in question 1.
Find the shared variable. When two tables or a table and a graph appear together, they connect through one variable (in Passage I, the site number). Use it to jump from one to the other.
Name the trend. "As distance increases, temperature goes up and oxygen goes down." Saying it first stops you from being pulled by choices that reverse one half.
Interpolate between neighbors. A value between two tested conditions almost always lies between their results. Extrapolating beyond the data works the same way: continue the pattern, but only if it's steady.
Estimate before calculating. There's no calculator on Science. Percents of 50 or 100, differences and "about twice" comparisons cover most of the math.

Association isn't proof. In Passage I, sites with more dissolved oxygen had more mayflies, but temperature and shade changed too. A question that asks what the data "support" can be answered with a relationship; one that asks what "caused" the change usually needs an experiment that changes one variable at a time.

Common PreACT Science traps

Most missed Science questions come from a short list of traps, and every one of them has a habit that beats it. Each appears in our practice set:

Wrong row or column. The choice is a real number from the table, just not the one asked for (questions 1 and 4). Point at the row before you read across.
Half-right trends. Choices pair a correct direction with a wrong one (question 2). Check both halves.
Count vs percent. 19 seeds is not 19% of 50 (question 8). Watch whether the question asks for an amount or a share.
Reading one column instead of the difference. Question 11 asks about the gap between two columns, which shrinks even though one column rises.
Confusing the control. The control is the condition without the factor being tested (question 7), not the one with the most extreme result.
Changing two things at once. A good follow-up experiment changes only the variable in question (question 12).
Mixing up the viewpoints. A choice that's true for Student 1 is wrong if the question asks about Student 2 (questions 14 and 18).
Answering from outside knowledge. Answer from the passage. On a Conflicting Viewpoints question, the "right" science can be the wrong answer if it isn't what that student said.

How much time per PreACT Science question?

On the PreACT and PreACT Secure, you have about 67 seconds per Science question; on the PreACT 9 Secure about 66 seconds, and on the PreACT 8/9 about 60 seconds. That time has to cover reading the passages too, so the real time per question is shorter.

Computed from ACT's Science question counts and times (PreACT FAQ, checked November 11, 2026). The per-passage time is our arithmetic, not an ACT figure; real passages vary in length.

Version	Science time	Per question	Per passage of 6 questions
PreACT and PreACT Secure	36 questions, 40 min	about 67 sec	about 6:40
PreACT 9 Secure	32 questions, 35 min	about 66 sec	about 6:34
PreACT 8/9	30 questions, 30 min	about 60 sec	about 6:00

A practical plan for the PreACT: about 6 to 7 minutes per six-question passage, with Data Representation passages faster and Conflicting Viewpoints slower. If a passage is taking far longer than that, guess on the hardest remaining question, mark it and move on; with no penalty for wrong answers, a guess is always better than a blank. With a minute left, fill in every unanswered question.

How PreACT Science relates to ACT Science

PreACT Science is a shorter version of ACT Science with the same passage formats and question styles. On the enhanced ACT, Science is also optional and doesn't affect the Composite; it has 40 questions in 40 minutes, about 60 seconds each (ACT test overview, PreACT FAQ).

Same skills. Reading data, understanding experiments and comparing explanations, so practice for one is practice for the other.
A little more time on the PreACT. About 67 seconds per question vs about 60 on the ACT. If you're on pace on the PreACT, work toward a slightly faster pace before the ACT.
Optional on both. On the ACT, you choose whether to add Science; on the PreACT, your school does. Check what the colleges or programs you're interested in ask for before you decide on the ACT.
Different scales. PreACT scores top out at 35 (or 32 or 30, depending on the version), and the ACT's at 36. Our PreACT to ACT score converter shows what a PreACT score suggests for the ACT.

If your school skips PreACT Science, it's still worth doing a few passages like the ones above in 9th or 10th grade, because the format takes practice and you'll meet it again if you add Science to the ACT. For full-length practice, ACT offers a free online PreACT Secure practice test with a scoring key on its Preparing for PreACT Secure page.

Frequently asked questions

Only if your school or district chooses to give it. Science became optional on the PreACT Secure and PreACT 9 Secure in spring 2026 and on the PreACT and PreACT 8/9 in fall 2026. The choice is made for the whole school or district, not by each student, so ask your counselor whether Science is on your test.

On the PreACT and PreACT Secure, Science has 36 questions in 40 minutes (30 of them scored). On the PreACT 9 Secure it has 32 questions in 35 minutes (26 scored). ACT lists 30 Science items for the PreACT 8/9 and has not yet published its new blueprint. Science always comes last, after Reading.

No, not anymore. Since fall 2026 (spring 2026 on the PreACT Secure), the PreACT Composite is calculated from English, Math and Reading only, the same as on the enhanced ACT. If your school gives Science, you get a separate Science score with three reporting category scores.

No. ACT's guides for the PreACT Secure and PreACT 9 Secure say calculators are not permitted on the Science section. The math you need is simple: reading values, comparing numbers, quick percents and spotting trends.

Not much. ACT says the passages draw on biology, chemistry, Earth and space sciences and physics, but advanced knowledge isn't required. The questions test how you read data, understand experiments and evaluate explanations, so practice with passages matters more than memorizing facts.

Yes. It uses the same three passage formats (Data Representation, Research Summaries and Conflicting Viewpoints) and the same kind of questions. ACT Science on the enhanced ACT is also optional and outside the Composite, with 40 questions in 40 minutes, about 60 seconds each; the PreACT gives about 67 seconds per question.

Last verified against ACT's PreACT FAQ, PreACT test guides and enhanced ACT overview: November 11, 2026.

Official sources

Related PreACT guides

Keep practicing for the PreACT

PreACT practice with explanations for every question, so you know what to work on before test day. Start with a free account.

Start practicing free