Write a net ionic equation to show that hydrofluoric acid , hf , behaves as an acid in water.

This equation shows how HF, hydrofluoric acid behaves in water. 
HF (aq) > H+ (aq) + F- (aq). In water acids will dissociate into positive cations and negative anions. The strength or weakness of an acid depends on its ability to dissociate in water. Substances that dissociate completely are strong acids while partial dissociation indicates a weak acid. HF is considered to be a weak acid because it does not completely dissociates in water. There is instead an equilibrium between HF molecules and the dissociates.