Which rule must be fulfilled by sharing or transferring electrons to create bonds in order for an element to be stable?

a scenario where a cell may be needed to perform a form of endocytosis is when transporting large molecules. a scenario where a cell may be needed to perform a form of exocytosis is when releasing the large molecule from the cell.

a=c and then d= c because of the band so you get ac/dc and you add them together you get sound waves