* Ionization Energy: Calcium has a lower ionization energy than sodium. This means it requires less energy to remove an electron from a calcium atom compared to a sodium atom. A lower ionization energy makes it easier for calcium to form a positive ion and participate in a reaction with oxygen.
* Electropositivity: Calcium is more electropositive than sodium, meaning it has a greater tendency to lose electrons and form a positive ion. This again makes it more reactive with oxygen.
* Reactivity Series: Calcium is located below sodium in the reactivity series of metals. This means calcium is more reactive than sodium.
Reaction Products:
* Sodium: Sodium reacts with oxygen to form sodium oxide (Na₂O), which can further react with water to form sodium hydroxide (NaOH).
* Calcium: Calcium reacts with oxygen to form calcium oxide (CaO), also known as quicklime. This reaction is highly exothermic and produces a bright light.
In summary: Both sodium and calcium are highly reactive with oxygen, but calcium is slightly more likely to react due to its lower ionization energy, greater electropositivity, and higher position in the reactivity series.
