Which best describes a mixture? It has a single composition, and it has a set of characteristics that does not change. It can have different compositions, but it has a set of characteristics that does not change. It has a single composition, but it has a set of characteristics that does change. It can have different compositions, and it has a set of characteristics that does change.

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 class of molecules functions as chemical signals? hormones water carbohydrates proteins

Why do cells appear different in distilled water than they do in 10% salt water?