Year 7 Science · Unit 4 · Lesson 3
Apply Worksheet
Learning Goals
True or false? Fix the false ones
Circle T or F. If a statement is false, correct it on the line.
1. You should write your results from memory after the test is finished.
Correct it:
2. The hypothesis is the step where you answer your question using the evidence.
Correct it:
3. A method is written so that someone else could repeat your test.
Correct it:
4. Communicating your results lets other people check or repeat your work.
Correct it:
5. Changing two things at once makes a test fairer, because you learn about both.
Correct it:
1. The Working Scientifically processes include four groups of skills. Name them.
Order the steps: coloured cups in the sun
Rahul investigates whether the colour of a cup changes how much the water in it warms up in sunlight. Number his steps from 1 (first) to 6 (last).
| Step | What Rahul does |
|---|---|
| Compares how much the water warmed up in each cup and looks for a pattern. | |
| Plans the test: identical cups except for colour, the same amount of water at the same starting temperature, the same sunny spot. | |
| Answers his question using the evidence. | |
| Predicts that the water in the black cup will warm up the most. | |
| Measures the water temperature in each cup after 30 minutes and writes it in a table straight away. | |
| Asks: “Does the colour of a cup change how much the water in it warms up in sunlight?” |
2. Noah compares two paper-plane designs. He throws design A indoors. His sister throws design B outside on a windy day. Design B flies further, so Noah says B is the better design. (a) Name two things, other than the design, that were not kept the same. (b) Explain why Noah’s conclusion cannot be trusted.
Read the data: Rahul’s results
Scenario
Rahul uses a black, a grey and a white cup, each holding 150 mL of water that starts at 20 °C. He repeats the test on three sunny days, with all three cups side by side each time.
| Cup colour | Day 1 | Day 2 | Day 3 | Average |
|---|---|---|---|---|
| Black | 14 | 15 | 13 | 14 |
| Grey | 10 | 11 | 9 | |
| White | 7 | 5 | 6 |
Source: sample class results for this worksheet.
3. Calculate the average rise for the grey cup and the white cup, and write them in Table 1.
Grey °C
White °C
4. Write a conclusion that answers Rahul’s question, using the averages. Then explain why he repeated the test on three days.
5. Evaluate this statement: “If a test gives the answer you expected, it must have been a fair test.”
True or false
1. False: record results in a table as you go. 2. False: that is the conclusion; a hypothesis is a prediction before testing. 3. True. 4. True. 5. False: change only one thing, or you cannot tell what caused the result.
Question 1
Questioning and predicting; planning and conducting; processing and analysing; communicating. All four = 2; two or three = 1. [2 marks]
Order the steps: coloured cups in the sun
Reading down the table as printed, the correct step numbers are 5, 3, 6, 2, 4, 1. In order: ask; predict; plan; measure and record; compare; answer the question.
Question 2
(a) Any two, 1 mark each: the thrower; indoors or outside; the wind. (b) Several things changed, so the wind or thrower, not the design, may explain it (1). [3 marks]
Question 3
Grey: (10 + 11 + 9) ÷ 3 = 10 °C (1). White: (7 + 5 + 6) ÷ 3 = 6 °C (1). [2 marks]
Question 4
Yes, colour changes how much the water warms (1): the darker the cup, the bigger the rise (black 14, grey 10, white 6 °C) (1). Repeating means one odd result, such as a cloudy moment, cannot fool him (1). [3 marks]
Question 5
Marking guide: 1 judgement: wrong; 1 a fair test changes only one thing and keeps the rest the same; 1 fairness depends on the method, not on matching the prediction; 1 an unfair test can give the expected answer by luck or through another variable (e.g. the wind helping Noah’s plane B); 1 systematic observations (measured, repeated, recorded as you go) let others check the result; 1 trust comes from a controlled method, not an expected answer. [6 marks]
Model answer: The statement is wrong. A fair test changes only one thing and keeps the rest the same, so fairness depends on the method, not the answer. An unfair test can give the expected answer by luck or through another variable: if Noah expected B to win, the wind could have given him that answer. Systematic observations let others check the result: we trust a controlled method, not an expected answer.
Common error: mixing up the hypothesis (a prediction) with the conclusion (the answer from evidence).