The equilibrium distance $r_0$ between two atoms in a molecule is called the bond length. Using the bond lengths of homogeneous molecules (like $\textrm{H}_2$, $\textrm{O}_2$, and $\textrm{N}_2$), one can estimate the bond length of heterogeneous molecules (like CO, CN, and NO). This is done by summing half of each bond length of the homogenous molecules to estimate that of the heterogeneous molecule. Given the following bond lengths: $\textrm{H}_2$ (= 74 pm), $\textrm{N}_2$ (= 145 pm), $\textrm{O}_2$ (= 121pm), $\textrm{C}_2$ (= 154 pm), estimate the bond lengths for: HN, CN, and NO.