7. Accurate results are close to the true value. 8. Precise results are close to each other in value. 9. A fair experiment has only one cause variable that is changed. 10. Ethics deals with moral principles. To work in an ethical way, scientists must not only ask ‘Can I?’, they need also to ask ‘Should I?’
11. Collected data can be used to identify patterns and relationships between variables. 12. Scientists reflect on their methods and results to evaluate them and to design further experiments.
13. Research is a way of collecting data from sources such as books and the internet.
Questions and Exercises K C
Key Concepts Rewrite the following sentences in your copybook and fill in the blanks. 1. List three types of investigation that can be used to test scientific hypotheses. (a) _____________ (b) _____________ (c) _____________.
2. When a scientist notices something it is called an ________________. 3. Data that can be measured is called ________________ data. 4. Data that is recorded without using measurements is called ________________ data. 5. Investigations that give similar results every time they are repeated are described as ________________.
6. Results that are close to the true value can be described as ________________. 7. Results that are close to each other in value can be described as ________________. 8. For each of the following set of results state whether they are reliable, accurate or precise. One or more descriptions may be possible: (a) Temperatures taken of a beaker of iced water: ________________________ 5°C
6°C 10.8 cm 4°C 11.2 cm 5°C
(b) Measurements of a line that is 13.5 cm: _____________________________ 11 cm
(c) A golfer hits a ball the following distances: ____________________________ 223 metres
221 metres 222 metres 221 metres
9. A variable is a factor that can ____________ . 10. A factor that does not change in an experiment is called a ________________.
