Should you take the Science section at all?
The honest answer is that it depends on where you are applying, and this is one of the few test-prep decisions where a couple of hours of research genuinely beats a couple of hours of studying.
Because Science no longer feeds the composite, taking it can only help your composite indirectly - it cannot raise it. What it does produce is a separate Science section score and a STEM score combining Science and Math. For an applicant to an engineering, health-sciences or research-heavy programme, that is a signal worth having. For an applicant to a humanities programme that reports composite scores only, it is an extra 40 minutes of fatigue for a number nobody will read.
- ✓Check each target programme's published testing requirements directly, and check them for your application year rather than relying on a summary.
- ✓Take Science if you are applying to STEM programmes, if a scholarship uses a STEM score, or if science is your strongest area and you want the separate score on record.
- ✓Consider skipping it if your target programmes look only at the composite, if your composite sections still need work, or if fatigue in a long test measurably damages your performance.
- ✓If in doubt on a first sitting, taking it costs you little - you learn how you perform, and a weak Science score does not drag down a composite it is not part of.
What the section actually tests
Students prepare for ACT Science by revising biology and chemistry, and that is close to the least efficient thing they could do. The section has historically been built from three passage formats: data representation, where you read graphs and tables; research summaries, where you compare related experiments; and conflicting viewpoints, where two or more scientists disagree and you evaluate their positions.
In all three, the information you need is supplied. What is being measured is how quickly and accurately you can extract a value from a figure, spot a trend, recognise what an experiment controlled for, and tell what a scientist claims from what the data shows. The small amount of assumed background knowledge is introductory level.
The practical consequence: your bottleneck is pace, not content. Forty questions in forty minutes is under a minute each, across passages you have never seen.
| Item | Detail |
|---|---|
| Status | Optional under the enhanced ACT |
| Questions | 40 |
| Time | 40 minutes |
| Counts toward composite | No - composite is English, Math and Reading |
| What it produces | A Science section score, and a STEM score combined with Math |
| Passage formats | Data representation; research summaries; conflicting viewpoints |
Practice: reading a data set
The table below is the kind of figure a data-representation passage is built around. A student measured the rate of an enzyme-catalysed reaction at a range of temperatures, holding everything else constant.
| Temperature (degrees C) | Reaction rate (micromoles per minute) |
|---|---|
| 10 | 4 |
| 20 | 11 |
| 30 | 24 |
| 40 | 38 |
| 50 | 21 |
| 60 | 3 |
Based on Table 1, at which temperature is the reaction rate greatest?
40 degrees C, where the rate is 38 micromoles per minute. This is the simplest question type on the section and it should take you a few seconds. The discipline worth building is answering it from the table alone without pausing to think about why - questions that ask why come later, and mixing the two is what costs time.
Which statement is best supported by Table 1?
That the rate increases with temperature up to a maximum and then decreases. The wrong answer the test will offer is that rate increases with temperature, which is true for the first four rows and false for the last two. ACT Science reliably includes a partially-true option that describes only part of the data, so always check the trend across the entire range before committing.
A student predicts the reaction rate at 45 degrees C. Which prediction is most reasonable?
A value between 21 and 38 - around 30. Interpolation questions ask you to read between two measured points, and the answer is bounded by the neighbouring values. Note that the answer is not simply the average, because the data are not linear here; the ACT usually gives options spread widely enough that identifying the correct interval is sufficient.
Two scientists disagree about why the rate falls above 40 degrees C. Scientist 1 argues the enzyme's structure is permanently altered at high temperature. Scientist 2 argues the substrate is being used up faster than it can be replaced. Which finding would most support Scientist 1?
Evidence that cooling the mixture back to 30 degrees C after heating does not restore the original rate. Scientist 1's claim is that the change is permanent, so the decisive test is reversibility. Adding more substrate restoring the rate would support Scientist 2 instead. Conflicting-viewpoints questions are answered by identifying what each position predicts, not by deciding who is scientifically correct.
Practice this now
The pacing method that fits 40 questions in 40 minutes
- ✓Go to the questions before reading the passage in full. Most questions send you to a specific figure, and reading the surrounding prose first is usually wasted time.
- ✓Read axis labels and units before anything else. A large share of wrong answers come from misreading which variable is on which axis, or missing a unit change between two figures.
- ✓Do conflicting-viewpoints passages last. They are the only format that genuinely requires reading, so they cost the most time per question.
- ✓Answer literal look-up questions immediately and without rereading. They are free marks and they fund the time you need elsewhere.
- ✓Never leave a blank - the ACT has no penalty for wrong answers.
- ✓Practise with a timer from the beginning. Untimed ACT Science practice measures a skill the test does not assess.