Here's why:

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

* Conductive: It's a good conductor of heat and electricity.

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

* Solid at Room Temperature: Sodium is solid at room temperature (except for mercury, which is a liquid metal).

These are all properties of metals.