Why would a metal explode like that just because it was put in water. Cesium compounds do not react violently with air or water and are generally very soluble in water. The Group 1 elements in the periodic table are known as the alkali metals. Lithium just sizzles on top of the water (see Table 1 for densities). Cesium releases enough energy that even a small piece blows up in water. As a group 1 element, caesium reacts violently with water. Sodium also floats on top of the water, it will ignite with a yellow orange flame most of the time however it does not explode. This is due to the fact that it is in the Alkali metals column, which all react with water. They include lithium, sodium and potassium, which all react vigorously with water to produce an alkaline solution. The metal darts across the surface of the water as alkali metals are less dense than water. Effervescence is observed. The reactivity increases as you descend the group. Cesium binds strongly to soil and concrete, but does … Potassium breaks apart, burning with a violet flame. Because Cs-137 bonds with chlorides to make a crystalline powder, it reacts in the environment like table salt (sodium chloride): Cesium moves easily through the air. Cesium dissolves easily in water. A small amount of lithium will float on water and burn. Pure cesium metal reacts violently with air and water, resulting in an explosion-like reaction. Please be specific and informative. Cesium in the Environment. The most important source of commercial cesium is a mineral known as pollucite, which usually contains about 5–32% cesium oxide (Cs 2 O). The cesium will react with the water and create an explosion. Sodium burns more readily. Rubidium ignites with a red flame. It does not explode. How (and why) do Cesium, rubidium, and Francium "Explode" when they are put in water.? 2. Francium is below cesium on the table and would react more readily and violently. Answer Save.