Chemical oxygen generators on spacecraft use a superoxide of this element in case of emergency. The 
Chemical oxygen generators on spacecraft use a superoxide of this element in case of emergency. The hydroxide of this element can be used to dry azides, and triamterene helps retain ions of this element in hypertension patients. Trifluoroborates of this element can be utilized instead of boronic acid in the Suzuki coupling. A carbonate of this element speeds up the Shi Epoxidation, but also reduces the stability of the oxidizing agent. This element occurs naturally in mineral form as (*) sylvite, and its flame test produces a bright pink color.  Its elemental form along with its hydroxide react explosively with water, and its cyanide is useful in electroplating. Often exchanged in cells for sodium ions, for 10 points, name this alkali metal with chemical symbol K.
Chemical oxygen generators on spacecraft use a superoxide of this element in case of emergency.
potassium (prompt on K before mention)