An  latex1  molecule travelling in the $x latex12 u_{\text{NO}} = -550\,\text{m}\cdot\text{s}^{-1}$ and an  latex2  molecule travelling at $u_{\text{O}_3} = +550\,\text{m}\cdot\text{s}^{-1} latex15 [\text{NO--O}_3]^{\ast} latex16 [\text{NO--O}_3]^{\ast} latex17 \text{NO}_2 latex18 \text{O}_2$ molecule in the right circumstances?