An element's atomic number is 81. how many protons would an atom of this element have? protons

Which compound contains both ionic and covalent bonds? a) hbr b)cbr4 c)nabr d) naoh

14. many depressants reduce small muscle control, making it harder for a. you to steer b. your mind to consider complex problems c. the eye to scan, focus, or stay still d. the kidneys to filter alcohol out of the bloodstream

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.