One reason that multiple approaches are often taken to answer a testable question is that scientists have different educational backgrounds and experiences.
• want to determine the single best way to find an answer.
often look for the quickest way to answer the question.
get tired of using the same approach every single time.

Compare and contrast physical changes with chemical changes.

The scheme below is from a series of reactions that are part of a synthesis of vitamin a. answer the following questions with reference to this scheme. (i) what is "reagent a"? (ii) draw a step-by-step mechanism which explains the formation of compound c from compound b (iii) which reagents would you use to form compound e from compounds c and d (reagents b and c)? for each reagent suggested above in (ii) explain the role of the reagent in the reaction to (iv) form compound e. you may wish to do this by drawing a mechanism. 1. addition of reagent a но reagent a 2. н,о" thо oh нон-с compound a. compound b. compound c .ch-оh 1. reagent b "сно 2. reagent c сh oh compound e. compound d.

Which of the following represents the ester functional group? a. -coo- b. -cho c. -cooh d. c=o