1. There is no one single way in which all scientists work. 2. Science is a process which is continually changing. 3. A scientific theory is a set of ideas about how some aspect of the world works. 4. Scientific theories are modified over time. 5. Scientific investigation is the process of gathering evidence and testing ideas to explain observations.
6. Socio-scientific issues are social issues that are related to science. 7. A hypothesis is an initial idea about how to explain scientific observations. 8. A controlled experiment is a test that involves changing one factor in order to see how it affects some other factor.
9. A variable is a factor that changes in an experiment or investigation. 10. The cause variable is the factor that you change in a controlled experiment. 11. The effect variable is the factor that may change as a result of this change. 12. Constants are factors that are kept the same in an experiment. 13. The control in an experiment is one where factors are not changed. It is used to compare with the findings of the experiments where factors are changed.
14. Observational experiments are useful when it is difficult to control or change variables.
15. Models can be used to carry out experiments that could not be carried out in the real world, such as experiments to predict the weather.
Questions and Exercises K C
Key Concepts Rewrite the following sentences in your copybook and fill in the blanks. 1. A set of ideas about how some aspect of the world works is called a _______________. 2. An initial idea about how to explain scientific observations is called a ______________. 3. Social issues that are related to science are called __________________ issues. 4. Scientists gather evidence to test their ideas by carrying out __________________.
K U
Knowledge and Understanding 1. Explain how a hypothesis develops into a theory.
2. Why do most scientific ideas need to be modified over time? 3. Give an example of a question that is not suitable for scientific investigation. 4. (a) Name three different strategies that scientists use to test their hypotheses. (b) Give a brief outline of each strategy.
