Chemical properties of Deuterium

Deuterium's chemistry closely parallels ordinary hydrogen's. Like H₂, it reacts with oxygen to form the deuterium analogue of water -- deuterium oxide, better known as heavy water:

It also reacts with the halogens to give the corresponding deuterium halides:

Deuterium exchange reactions. Beyond simply reacting the way H₂ does, deuterium has a distinctive reaction type of its own: it can reversibly replace ordinary hydrogen already present in a compound, either partially or completely depending on the reaction conditions, whenever the compound is treated with D₂ gas or heavy water. Examples:

$2\,NH_3 + 3\,D_2 \rightarrow 2\,ND_3 + 3\,H_2$ …