In chemistry, an alkali (/ˈælkəlaɪ/; frae Arabic: al-qaly القلي, القالي ) is a basic, ionic saut o an alkali metal or alkaline yird metal chemical element. Some authors alsae 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 fur basic, especially fur 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.