Which layer of the atmosphere is closest to the surface of Earth? mesosphere
thermosphere
troposphere
stratosphere

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.

If you try to move a piano and are unable to move it, did you perform any work in the scientific sense of the word? yes no correct anwser get brainliest

The concentration of ionic substances is important for the heart to beat. your heart responds to electrical impulses that travel through heart cells that are made up mostly of water. which properties of ionic compounds are important to support this function? solubility in water conductivity crystalline melting point