Elements in group Ia of the Periodic Table. In order of increasing Atomic Number, they are Lithium, Sodium, Potassium, Rubidium, Cesium, and Francium. They are softer than other Metals, and have lower Melting Points and densities (see Density). All react violently with
Water, releasing Hydrogen and forming hydroxides. They tarnish rapidly, even in Dry Air. They never occur uncombined in nature.