Why were microscopes essential in the discovery of cells pls stay of if u dont know pls... im trynna pass not trynna be rude

C I believe if that's wrong then it's A. :)

u i forgot the answer?

the number of valence electrons for each molecule or ion is shown beneath the structure. remember hydrogen will not have more than two electrons. this hydrogen is part of a covalent bond (sharing two electrons). a double bond here would cause hydrogen to share four electrons with phosphorus.