The elements are divalent in almost all of their compounds, and these compounds in solution give simple, divalent, colorless ions.
Univalent hydrogen and divalent oxygen will then have the symbols H- and -O-.
In the other series the metals are divalent and resemble magnesium salts in formulas.
In the divalent oxygen we meet with the modification called ozone, which, although unstable, changes but slowly into oxygen.
Copper, like iron, forms two series of compounds: in the cuprous compounds it is univalent; in the cupric it is divalent.
Silver acts as a univalent element and calcium as a divalent element in the formation of their respective nitrates and chlorides.
A divalent element, on the other hand, will combine with two atoms of a univalent element.
But if a divalent atom is in question the charge carried is double, and, similarly, a trivalent atom carries a triple charge.
Thus hydrochloric acid is better than sulphuric, on account of the stabilizing effect of the divalent SO4— ion on a negative sol.
divalent di·va·lent (dī-vā'lənt)