Cesium, like the other alkali metals, readily dissolves in liquid ammonia to produce "solvated electrons" and cesium cations. The solvated electrons possess a characteristic blue color caused by transmitted light and are paramagnetic. At high concentrations the cesium-ammonia solution becomes quite viscous and turns bright gold due to reflected light. On exposure to oxygen, cesium readily forms seven different oxides ranging from Cs7O to CsO3