6.Scientific Method â amajor theme this term. You have heard that sunscreen with an SPF greater than 50 doesnot provide additional protection from the sunâs rays. Youset up 2 groups, each with 25 people. The individuals in bothgroups have similar skin pigmentation. Formulate a hypothesis. Design anexperiment. What is the independent variable? The dependentvariable? State your results and conclusion.
12.A student's account of anexperiment reads as follows:
I placed some diastase powder(a starch-digesting enzyme) in some starch solution in a test-tube. By taking samples from the tube and testing them with iodine,I found that the starch gradually disappeared. I repeated theexperiment but added a few cubic centimetres of dilute sodiumcarbonate (an alkali) to the starch solution before adding thediastase. The starch took longer to disappear. I concluded thatdiastase had an optimum pH of 7 (neutral).
Critique (a) the student's experimental design (as judged by thereport), (b) thestudentâs
interpretation of the results.(
6.Scientific Method â amajor theme this term. You have heard that sunscreen with an SPF greater than 50 doesnot provide additional protection from the sunâs rays. Youset up 2 groups, each with 25 people. The individuals in bothgroups have similar skin pigmentation. Formulate a hypothesis. Design anexperiment. What is the independent variable? The dependentvariable? State your results and conclusion.
12.A student's account of anexperiment reads as follows:
I placed some diastase powder(a starch-digesting enzyme) in some starch solution in a test-tube. By taking samples from the tube and testing them with iodine,I found that the starch gradually disappeared. I repeated theexperiment but added a few cubic centimetres of dilute sodiumcarbonate (an alkali) to the starch solution before adding thediastase. The starch took longer to disappear. I concluded thatdiastase had an optimum pH of 7 (neutral).
Critique (a) the student's experimental design (as judged by thereport), (b) thestudentâs
interpretation of the results.(
