Alkali metals are a group of soft, low-density, low-melting, highly reactive metallic elements, including lithium, sodium, potassium, rubidium, cesium, and francium. They form alkalies when they combine with other elements. Because their atoms have only one electron in the outermost shell, they are very reactive chemically. They react rapidly, even violently, with water.
YouTube link
(via Everlasting Blort)The Presurfer