You think probable to caesium (Cs).
Francium and cesium
These elements are francium and lithium.
Alkali metals in the first group compose the most reactive family of metals.
The most reactive elements in the group of alkali metals are cesium and francium. They are highly reactive due to their low ionization energy and tendency to lose their outermost electron to achieve a stable electron configuration. Due to their reactivity, they are stored under oil to prevent reaction with moisture in the air.
Sodium and Chlorine = Sodium Chloride Potassium and Iodine = Potassium Iodide
The reactive group of all metals consists of elements located in Group 1 and Group 2 of the periodic table, known as the alkali metals and alkaline earth metals, respectively. These metals are highly reactive due to their tendency to lose electrons and form positive ions.
The alkali metals (Group 1) and the halogens (Group 17) are known to be very reactive elements. Alkali metals react vigorously with water, while halogens are highly reactive nonmetals that readily form compounds with other elements.
The group containing the most reactive elements is Group 1, also known as the alkali metals. These elements include lithium, sodium, and potassium, which are highly reactive due to their low ionization energies and tendency to lose electrons to form positive ions.
Elements in group 1 (alkali metals) are typically more reactive with oxygen compared to group 11 (coinage metals). This is because alkali metals have a lower ionization energy and are more likely to form ionic compounds with oxygen.
The alkali and alkaline earth metals are the least electro negative elements, and the halogens are the most electro negative elements.
The alkali metals group, located in Group 1 of the periodic table, is the most reactive group of elements. These elements have one electron in their outermost shell, making them highly reactive as they seek to lose this electron to achieve a stable electronic configuration.
The most reactive metals are the alkali metals in group 1a.