Alkali+Metals

=Alkali Metals= There are five Alkali Metals; Potassium, Rubidium, Lithium, Sodium, and Cesium

Potassium is

Cesium is an incredibly reactive element, with only 1 out of the 17 possible valence electrons. Cesium is liquid at about 83 degrees, almost room temperature. Its atomic number is 55, and its atomic mass is about 132.91. Cesium reacts violently with water, exploding instantly when comes in contact of it. Here's a video of cesium exploding in water

cesium explodes