A Fair Test ETV Unit 1 Introdcuing Science

A Fair Test ETV – Unit 1 – Introdcuing Science

1. The inquiry in this programme is about the cleaning effect of two brands of detergent. the cleaning effect of two brands of washing powder. the effect of temperature on the cleaning effect of washing powder. the effect of stirring on the cleaning effect of washing powder

2. The brands of the washing powders mentioned in the programme are Rabbit and Swip Plus Rabbit and Swip Swim and Rabbit Swan and Rabbit

3. The observation Charles made was Swan has better cleaning effect when compared with Rabbit. The stain on the cloth in clean water was still there, but the stain on the cloth in water with washing powder has disappeared. Rabbit has better cleaning effect when compared with Swan. Higher water temperature has better cleaning effect.

4. Based on the observation, Charles and Betty concluded that Swan has better cleaning effect when compared with Rabbit. Higher water temperature has better cleaning effect. The washing powder did clean stains on the cloth. Rabbit has better cleaning effect when compared with Swan.

5. The hypothesis Charles and Betty put forward is The Rabbit brand is more effective than the Swan brand in cleaning stains. The Swan brand is more effective than the Rabbit brand in cleaning stains. Higher water temperature has better cleaning effect. Stirring the washing powder solution can improve the cleaning effect.

6. Which of the followings are the mistakes made by Charles and Betty in their experimental design? (I) The stains were different in size (II)They use more Swan washing powder than they should have. (III)The beaker with Rabbit Brand washing powder was larger. (I), (IV)They stir the water with the Rabbit brand washing powder more frequently. (I) only (I) & (III) only (III) & (IV) only (I), (III) & (IV)

7. According to the programme, what should first be done when we perform a scientific experiment? Design the experiment and predict the results. Identify a variable to be changed. Identify a variable to be measured. Identify a variable factor to be test.

8. Which of the following about control experiment is correct? A control is needed because the experiment may not be able to give clear-cut results. The control experiment should be identical in all aspects except for the factor being tested. The control must be performed together with the experiment. Not all fair tests require the setting up of control experiment.