Classify the following species by decreasing basicity:
(Basicity is the ease with which the material captures an $H^+$ ion). Note that $O$ and $N$ have doublets that can capture this ion.
$1$ $ \gt$ $ 3$ $ \gt$ $ 6 $ $\gt$ $ 4$ $ \gt$ $ 2$ $ \gt$ $ 5$ $ \gt$ $ 7$
The negative charge repels doublets from the nucleus and makes them more capable of capturing $H^+$
