Which group of atomic models is listed in historical order from the earliest to the most recent?

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.

An atom's configuration based on its number of electrons ends at 3p4. another atom has seven more electrons. starting at 3p, what is the remaining configuration? 3p63d34s2 3p43d54s2 3p64s23d3 3p44s23d

Ab c or d ? i’m not sure what the answer is