The correct order of bond length is :-

Which one is paramagnetic and has the bond order $1/2$?

What is the bond order of the $O_2$ molecule?

Which of the following species is paramagnetic?

Given below are two statements:
Statement $I$: $A$ $\pi$ bonding $MO$ has lower electron density above and below the inter-nuclear axis.
Statement $II$: The $\pi^*$ antibonding $MO$ has a node between the nuclei.
In the light of the above statements,choose the most appropriate answer from the options given below:

Find out the bond order in $He_2, He_2^{+}, O_2$ and $O_2^{+}$ respectively.