# Investigation guide8 (updated oct 2016 for grade 8)

5 Oct 2016
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### Investigation guide8 (updated oct 2016 for grade 8)

• 1. Planning Research question: How does changing _____ (units) affect the _____ (units) of ______ Background: Provide a context for the investigation Provide overview of known related Science Variables Factor Description Independent Temperature Temperature will be changed by heating with a Bunsen burner and measurements will be made every 10 degrees as measured by a thermometer Dependent Conductivity Measured using a LabPro conductivity probe Fixed or controlled Controlled variables should be values which are actually maintained by action not just using the same equipment
• 2. Method A list of the equipment including details of type and amount A labelled diagram should be used to support method The method should consist of numbered single instruction sentences Must include how to alter the independent variable, how to measure the dependent variable and how to control other variable Must include taking at least 5 different values each with 3 trails Highlight any safety precautions made in an additional box Example 1. Set up equipment as shown in the diagram. 2. Use a measuring cylinder to collect 20ml of hydrochloric acid.
• 3. Data Collection Independent Variable ± uncertainty (units) Dependent Variable (units) Trial 1 Trial 2 Trial 3 Average Volume of acid (ml) Conductivity (μS/cm) Trial 1 Trial 2 Trial 3 Average 10 20 30 40 50 General example Example Qualitative notes including any anomalies should be recorded after the results table Remember you target is 5 sets of data each repeated 3 times
• 4. Data Analysis •Construct a scatter graph with a trend line – the independent variable should always be on the x-axis •Describe the graph trend in words and with a mathematical formula. E.g. A straight line of best fit with a positive gradient (y = 84x-2)
• 5. Conclusion • Make a conclusive statement – what did you find out • Offer a scientific explanation • Comment on the validity of your findings • Compared to theory • Showing consistency of data
• 6. Evaluation Issue Improvement Volume of acid not controlled Measure 100ml with measuring cylinder The order of the issues should be used to show the relative impact on the experiment – with the greatest impact first