Write the general formula of an alum, representing an atom of an alkali metal by X and an atom of a trivalent metal by Y.
Barium nitrate, used with a neutral solution, is the group reagent in the absence of metal ions other than the alkali metal ions.
alkali metal n.
Any of a group of soft, white, low-density, low-melting, highly reactive metallic elements, including lithium, sodium, potassium, rubidium, cesium, and francium.
|alkali metal |
Any of a group of soft metallic elements that form alkali solutions when they combine with water. They include lithium, sodium, potassium, rubidium, cesium, and francium. Except for cesium, which has a gold sheen, alkali metals are white. The alkali metals have one electron in their outer shell, and therefore react easily with other elements and are found in nature only in compounds. See Periodic Table.