We can assign oxidation number to each element in a compound to
keep track of electrons in oxidation
Oxidation numbers can be zero, positive or negative numbers. For this course,
you'll only encounter oxidation numbers as integers. Aside from the simple
ions in the compound, oxidation numbers bear no real physical meaning.
In polyatomic compounds which contain polyatomic
ions*, elements in polyatomic ions do not have
measurable ionic charge. For example, in sodium nitrate, NaNO3,