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