The diagrams below shows the structure of sodium chloride (NaCl), which is considered an extended structure. What statement best describes the structure of sodium chloride? Group of answer choices It is a simple molecule composed of one element. It is a crystal lattice composed of one element. It is a simple molecule without a repeating pattern. It is a crystal lattice that has a repeating pattern. I NEED THE ASNWER ASAP I'M IN A RUSH THX :D

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.

When the mercury level in a barometer decreases that atmospheric pressure has

You wish to prepare a buffer consisting of acetic acid and sodium acetate with a total acetic acetate plus acetate concentration of 250 mm and a ph of 5. what concentrations of acetic acid and sodium acetate should you use