Coaching Centre
Chapter 1 review and test
Every skill from the chapter as one checklist for planning an investigation, the key words, and a chapter test with multiple choice, sorting and extended responses with marking guidelines.
The skills in this chapter aren't separate topics. They are the steps of one investigation, in order. If you can walk through this list for any experiment, you can answer almost any "working scientifically" question in an exam.
An investigation from start to finish
| Step | Check you can… | Topic |
|---|---|---|
| 1. Question | Turn a vague question into a testable one; tell science questions from opinion questions | 1A |
| 2. Hypothesis | Write "If … then … because …" with a measurable outcome | 1A |
| 3. Variables | Name the IV, DV and at least three controlled variables | 1E |
| 4. Equipment | Choose the right equipment for each job and draw the set-up as a 2D diagram | 1B |
| 5. Safety | Identify hazards, read pictograms and say how to reduce each risk | 1C, 1D |
| 6. Method | Write numbered steps with repeat trials so anyone could follow them | 1H |
| 7. Measure | Use SI units, read scales without parallax error, and record in a proper table | 1G |
| 8. Observe | Record qualitative and quantitative observations, and keep inferences separate | 1F |
| 9. Graph | Choose column or line, and draw it with labelled axes, units and a line of best fit | 1H |
| 10. Discuss and conclude | Describe the trend with data, explain it, judge validity and reliability, suggest improvements, answer the aim | 1H |
Words you must be able to use
testable question · hypothesis · prediction · evidence · pseudoscience · equipment · apparatus · scientific diagram · hazard · risk · GHS pictogram · safety flame · heating flame · independent variable · dependent variable · controlled variable · fair test · repeat trials · average · outlier · valid · reliable · accurate · precise · observation · qualitative · quantitative · inference · SI units · prefix · scale interval · meniscus · parallax error · aim · method · results · discussion · conclusion · line of best fit
Chapter 1 test
Which question can be answered by a fair test in a school lab?
You can change the length and time the swings.
"If more detergent is added to bubble mixture, then bigger bubbles can be blown." In this hypothesis, the independent variable is
Detergent is what is changed; bubble size is measured.
"Apparatus" is best described as
Equipment is one item; apparatus is the set-up.
A student gets a chemical splash in the eye. They should
Water, straight away, for a long time.
To change a yellow Bunsen flame to a blue one you
More air mixing with the gas gives complete combustion: blue and hotter.
Which is an inference?
"Has a disease" explains the spots; it isn't directly observed.
0.25 L is equal to
0.25 × 1000 = 250 mL.
A student's three trials are 4.1 s, 4.3 s and 4.2 s. A classmate's are 3.0 s, 5.5 s and 4.1 s. The first student's results are more
Repeats that agree closely = reliable.
Which graph suits "number of people in a class with each eye colour"?
Eye colour is a category.
The meniscus in a measuring cylinder of water should be read
Bottom of the curve, eye level, cylinder on a flat bench.
Which is the main difference between science and pseudoscience?
Testing and repeatability are the heart of science.
The conclusion of a report should
Aim and conclusion are a matched pair.
Sort each skill into the stage of an investigation where you use it.
Design an investigation to find out whether the temperature of a tennis ball affects how high it bounces. Include a hypothesis, the independent, dependent and controlled variables, a brief method with repeat trials, one safety precaution, and the type of graph you would draw.
Hypothesis: If the tennis ball is warmer, then it will bounce higher, because the air inside will be at a higher pressure and the rubber will be more flexible. IV: temperature of the ball. DV: bounce height (cm). Controlled: the same ball, the same drop height (1.5 m), the same floor surface, releasing the ball without pushing it, measuring to the bottom of the ball at its highest point. Method: 1. Put the ball in a freezer for 30 minutes, measure its temperature with a probe against its surface. 2. Hold it with its bottom at the 150 cm mark of a metre rule taped to a wall and release it. 3. Film the bounce on a phone in slow motion beside the rule and read the highest point. 4. Repeat three times quickly and average. 5. Repeat steps 2–4 for the ball at room temperature, and after 10 minutes in warm (not boiling) water dried with a towel. Safety: use warm tap water, not boiling water, to avoid scalds, and wipe up spilled water so nobody slips. Graph: a line graph, because temperature is continuous.
Here is part of a student's report. Identify four mistakes and explain how to fix each one.
Aim: To see what happens to plants. Results: Plant A grew 3, plant B grew 45 mm. Plant B grew more because the fertiliser works. Graph: points joined dot-to-dot with no axis labels. Conclusion: The experiment worked.
1. The aim is vague. It should name the variables: "To investigate whether adding fertiliser affects how tall bean plants grow in two weeks." 2. "Grew 3" has no unit, and the two results are in different forms. Write both in mm (e.g. 30 mm and 45 mm). 3. "Because the fertiliser works" is an inference, so it belongs in the discussion, not the results. 4. The graph should have axis labels with units and, since plant A and plant B are categories, it should be a column graph, not dots joined up. 5. "The experiment worked" doesn't answer the aim. The conclusion should say: "The plant given fertiliser grew 15 mm more than the plant without, which supports the hypothesis."