Tantalum is a heavy, hard gray metal. Pure tantalum is ductile and may be drawn into very fine wire. Tantalum is practically immune to chemical attack at temperatures lower than 150 °C.

It is only attacked by hydrofluoric acid. Alkalis attack tantalum very slowly. At higher temperatures, tantalum is more reactive. The melting point of tantalum is very high, exceeded only by that of tungsten and rhenium.