Francium is most reactive - the Pauling electronegativity is calculated to be 0,7.
Francium is an alkali metal, similar to caesium. Water (H2O) is a compound,not an element. Francium, although it is believed to have never been tested, is thought to have been the most reactive element with water. It is among the alkali metals in group 1 on the periodic table of elements.
Supposing you mean cesium, I would say no. You see, when francium and water are mixed they react much more violently than cesium in water, causing a greater explosion. Therefore, cesium would combine more rapidly.
Francium would combine with water more readily than cesium. Francium is the most reactive alkali metal due to its position in the periodic table, so it would react more violently with water compared to cesium.
Probable francium would react more violent.
Very probable the reaction of francium should be more violent.
Francium is a highly reactive alkali metal that readily loses its single valence electron to form a +1 cation. It would react violently with water, producing hydrogen gas and releasing a significant amount of energy. Due to its extreme rarity and radioactivity, francium's reactivity has not been extensively studied.
Cesium is, except for Francium, the most reactive element of the alkaline metals. It explodes in water because it rapidly evolves Hydrogen gas and heat. The explosion results from the hydrogen gas blowing the boiling water out of the container and then igniting.
Caesium has the most explosive reaction. It is possible that francium is even more reactive but little is known of its properties.
Caesium belong to Group (1) The Alkali metals. Since it is the lowest in the Group , except for 'Francium', its reactivity with water and oxygen is 'explosive'. Going down the Group (1) the elements are , with increasing reactivity , Lithium, Sodium, Potassium, Rubidium, Caesium, and Francium. You will not find francium in the open lab. as it is radio-active.
Rubidium, caesium and francium. Potassium will generate enough heat to ignite the hydrogen produced in the reaction but the reaction is not really explosive.
Francium chloride is a radioactive chemical compound with the formula FrCl. It is predicted to be a white solid and is soluble in water. Its properties resemble caesium chloride. It is produced by the reaction of hydrochloric acid with francium metal. Source: Wikipedia
Caesium + water ------> Caesium hydroxide + Hydrogen