Reaction of tantalum with acids
Tantalum does not react wwith most acids, but does dissolve in hydrofluoric acid, HF, and oleum (a solution of sulphur trioxide, SO3, in sulphuric acid, H2SO4; also called fuming sulphuric acid).
Reaction of tantalum with air
Tantalum is passivated by a thin layer of tantalum oxides on the surface, and does not otherwise react with air under normal conditions.
Reaction of tantalum with halogens
Tantalum reacts with halogens upon heating, forming the corresponding Ta(V) halides.
2 Ta(s) + 5 F2(g) TaF5(s) [white]
2 Ta(s) + 5 Cl2(g) TaCl5(l) [white]
2 Ta(s) + 5 Br2(g) TaBr5(s) [pale yellow]
2 Ta(s) + 5 I2(g) TaI5(s) [black]
Reaction of tantalum with water
Tantalum does not react with water under normal conditions.