* Sodium (Na) is located in period 3 of the periodic table.

* It is an alkali metal, and alkali metals are known for being highly reactive.

Here's why:

* Electron Configuration: Sodium has a single valence electron in its outermost shell. This electron is easily lost, making it highly reactive.

* Electropositivity: Sodium is very electropositive, meaning it readily loses its electron to form a positive ion (Na+).

* Reactivity with Water: Sodium reacts violently with water, producing hydrogen gas and heat, which can cause explosions.

Let me know if you have any other questions!