A substance that has a pH greater than 7, typically a soluble base that reacts with acids to form salts.
Sodium hydroxide is a common alkali used in many industrial processes.
A group of chemical elements in the periodic table known as the alkali metals, which includes lithium, sodium, potassium, rubidium, cesium, and francium.
Alkali metals are highly reactive, especially with water.
Soluble mineral salts or compounds of alkali metals naturally occurring in some soils or water.
Excessive irrigation can leave alkali on the surface of the fields.