* Electropositivity: Francium is the most electropositive element, meaning it readily loses its outermost electron to form a positive ion (cation). This strong tendency to lose electrons makes it extremely reactive. Sodium, while reactive, is less electropositive than francium.
* Atomic Size: Francium is much larger than sodium. This larger size means its outermost electron is further from the nucleus and held less tightly, making it easier to lose and react.
* Ionization Energy: Francium has a lower ionization energy than sodium, meaning it requires less energy to remove an electron.
In summary: Francium's high electropositivity, large atomic size, and low ionization energy combine to make it far more reactive with oxygen than sodium.
Note: Francium is incredibly rare and radioactive, so these reactions are not something you would observe in a typical lab setting.
