Most of an atom's mass is contained in the what

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.

Suppose the universe were completely empty except for one object-a solid sphere moving through space of 100 km/s. what sort of path would the object be moving in? explain your answer

What type of chemical reaction occurs between silver nitrate (agno3) and copper (cu)? the equation i was given is 2agno3 + cu —> 2ag+ cu(no3)2.