Here's why:

* Shiny and lustrous: Sodium has a silvery-white, shiny appearance.

* Good conductor of heat and electricity: Sodium readily conducts heat and electricity.

* Malleable and ductile: Sodium can be hammered into thin sheets (malleable) and drawn into wires (ductile).

* Solid at room temperature: Most metals are solid at room temperature, and sodium is no exception.

* Reacts with nonmetals: Sodium readily reacts with nonmetals like chlorine to form ionic compounds.

These properties are characteristic of metals.