Year 8 Science · Unit 4 · Lesson 14
Apply Worksheet
Learning Goals
Plan the investigation
Scenario
Complete the planning for this mini investigation: "Does the temperature of water affect how quickly sugar dissolves?"
(a) Write an if-then-because hypothesis for this investigation.
(b) Identify the independent variable, dependent variable, and three controlled variables.
| Independent variable | |
| Dependent variable | |
| Controlled variables (list 3) |
(c) Design a data table with correct headings and units. Include columns for the IV, three trial readings, and an average.
Analyse the data
Results data
A student collected the following data for the sugar-dissolving investigation:
| Temperature (°C) | Trial 1 (s) | Trial 2 (s) | Trial 3 (s) | Average (s) |
|---|---|---|---|---|
| 20 | 80 | 84 | 82 | |
| 40 | 48 | 51 | 47 | |
| 60 | 24 | 23 | 25 |
(a) Calculate the average dissolving time for each temperature. Show your working for one calculation.
(b) Describe the trend shown in the results. Use specific data values.
(c) Write a complete CER conclusion for this investigation. Include a Claim (answers the research question), Evidence (two data values), and Reasoning (why temperature has this effect).
1. What would you do if one of the trial values was very different from the other two? Explain using the term "outlier".
2. Would a bar graph or a line graph be more appropriate for displaying this data? Explain why.
Wrap Up
In one sentence, explain why calculating averages improves the reliability of your results.