In chemistry, an alkali (//; frae Arabic: al-qaly القلي, القالي ) is a basic, ionic saut o an alkali metal or alkaline yird metal chemical element. Some authors an aa define an alkali as a base that dissolves in watter. A solution o a soluble base haes a pH greater nor 7.0. The adjective alkaline is commonly, an alkalescent less eften, uised in Inglis as a synonym for basic, especially for soluble bases. This broad uise o the term is likely tae hae come aboot acause alkalis wur the first bases kent tae obey the Arrhenius defineetion o a base, an thay are still amang the maist common bases.