(physics) Any of several series of spectral lines of hydrogen that correspond to quantum transitions between the various allowed energy levels of the hydrogen atom.

(inorganic chemistry) The acid sodium salt of arsenic acid, Na₂HAsO₄

plural of normal hydrogen electrode

plural of standard hydrogen electrode

(physics, chemistry) Alternative name for the standard hydrogen electrode; an electrode with a standard electrode potential of zero; used as a standard against which other electrodes are measured.

plural of hydrogen gas electrode

sodium bicarbonate (NaHCO₃)

(inorganic chemistry) The acid sodium salt of phosphoric acid, Na₂HPO₄

plural of sodium hydrogen carbonate

(chemistry) potassium bicarbonate