Dihydrogen reacts with dioxygen $(O_2)$ to form water. Write the name and formula of the product when the isotope of hydrogen which has one proton and one neutron in its nucleus is treated with oxygen. Will the reactivity of both the isotopes be the same towards oxygen? Justify your answer.

(N/A) The isotope of hydrogen which contains one proton and one neutron is deuterium $(D)$.
When dideuterium $(D_2)$ reacts with dioxygen $(O_2)$,the product formed is deuterium oxide $(D_2O)$,also known as heavy water.
The chemical equation is: $2D_{2(g)} + O_{2(g)} \xrightarrow{\Delta} 2D_2O_{(l)}$.
The reactivity of $H_2$ and $D_2$ towards oxygen is not the same.
This is because the $D-D$ bond is stronger than the $H-H$ bond due to the higher mass of deuterium,which leads to a lower zero-point energy.
Consequently,$H_2$ is more reactive than $D_2$ towards oxygen.