* Both sodium and francium are alkali metals. Alkali metals are in group 1 of the periodic table and have a +1 charge when they form ions.
* Alkali metals are highly reactive, especially francium. Francium is the most reactive element known. This extreme reactivity makes it very difficult to isolate and study.
* Similar reactivity prevents compound formation. Since both sodium and francium have the same tendency to lose one electron and become positively charged ions (Na+ and Fr+), they would not readily bond together.
Instead of forming a compound, sodium and francium would likely react with other elements, such as halogens (like chlorine or bromine) to form ionic compounds.
