RICAS Scientific Inquiry 2 — Questions and Answers
Question 1: A student wants to test whether salt concentration affects how fast water evaporates. Which variable should be kept the same throughout the experiment?
- The amount of water in each container
- The amount of salt added
- The temperature of the room (Correct answer)
- The time between measurements
Correct answer: The temperature of the room
Temperature must be controlled (kept constant) so it does not affect evaporation rate and confound the results.
Question 2: After completing an experiment, a scientist finds results that contradict her hypothesis. What should she do next?
- Change the data so it matches the hypothesis
- Repeat the experiment to confirm the results, then revise the hypothesis (Correct answer)
- Ignore the results and start a new experiment
- Publish the original hypothesis without the data
Correct answer: Repeat the experiment to confirm the results, then revise the hypothesis
Scientists repeat experiments to verify unexpected results, then revise or reject the hypothesis based on evidence.
Question 3: Which type of graph is BEST for showing how a plant's height changes over 30 days?
- Bar graph
- Pie chart
- Line graph (Correct answer)
- Venn diagram
Correct answer: Line graph
A line graph is best for showing changes in a variable over time.
Question 4: A student measures the mass of a rock three times and gets 45 g, 46 g, and 45 g. These results are best described as:
- Accurate but not precise
- Precise but not accurate
- Both accurate and precise
- Precise, assuming the true mass is near 45 g (Correct answer)
Correct answer: Precise, assuming the true mass is near 45 g
Precision means repeated measurements are close together; accuracy requires knowing the true value to compare against.
Question 5: What is the purpose of a control group in a scientific experiment?
- To test multiple variables at once
- To provide a baseline for comparison with the experimental group (Correct answer)
- To make sure the experiment runs faster
- To eliminate the need for repeated trials
Correct answer: To provide a baseline for comparison with the experimental group
The control group is not exposed to the experimental treatment and serves as a standard to compare results against.
Question 6: A student observes that plants near the window grow taller than plants in a dark corner. This observation leads to the question: Does light affect plant growth? What is the NEXT step in the scientific method?
- Draw a conclusion
- Conduct an experiment
- Form a hypothesis (Correct answer)
- Collect background research
Correct answer: Form a hypothesis
After asking a question, the next step is to form a testable hypothesis before designing an experiment.
Question 7: Which statement is an example of a quantitative observation?
- The solution turned blue.
- The flower smells sweet.
- The caterpillar is about 4.2 cm long. (Correct answer)
- The rock feels rough.
Correct answer: The caterpillar is about 4.2 cm long.
Quantitative observations include numbers and measurements, while qualitative observations describe qualities without numbers.
RICAS Scientific Inquiry 2
A student wants to test whether salt concentration affects how fast water evaporates.
Which variable should be kept the same throughout the experiment?