Along with sodium and tartrate, this substance makes up Rochelle's Salt, the main ingredient in baking powder.
Along with sodium and tartrate, this substance makes up Rochelle's Salt, the main ingredient in baking powder. This element's chloride is used for executions. The ratio of this element's concentration to those of nitrogen and phosphorous is used to label (*) fertilizer. The hydroxide of this element is known as lye, and this element's isotope forty decays into argon. For 10 points, name this third-heaviest of the alkali metals, with atomic number nineteen and atomic symbol K.
Along with sodium and tartrate, this substance makes up Rochelle's Salt, the main ingredient in baking powder.
{potassium} [or K before it is read]