Achemist examines an ionic compound that contains magnesium and one other element. she
doesn't know what that element is, but she knows there are two atoms of that element for every
magnesium atom. to which group does the unknown element belong?

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.

answer; the numbers of valence electrons in the acetic acid molecule (ch3co2h) is 24;