Yes, I know about significant figures. In fact, I considered adding a note about sig figs before deciding it was too minor of a nitpick to elaborate on. Elsewhe

Yes, I know about significant figures. In fact, I considered adding a note about sig figs before deciding it was too minor of a nitpick to elaborate on. Elsewhere in this thread, people have already listed these masses to much greater precision than almost anyone needs (including me, a practicing physicist); obviously people can infer I'm rounding from context. Of course, if you were to present the masses this way without context, you should add a note about rounding.