The image below shows the Lake Mead Recreation Area, which is near the Grand Canyon The diagram shows the
ages of layers of rock in one region of the park, The layers
at this location are fairly smooth and distinct
Private
What are these smooth, distinct layers most directly evidence of?
A Soll creep along the rocky cliffe
B. Many landslides and mudslides
6. Extensive chemical weathering
D. Many, many years of deposition

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.