need to know the measurement of the water- confusing me how to 21 comes before 20 thought, and how to find if of course

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.

56 moles of   lieter in chemistry

answersilicon (si); oxygen (o);