Chemical Bonding and Molecular Structure — Prelims Questions

Which of the following molecules has a trigonal planar geometry and is $sp^2$ hybridized?

Which of the following species is paramagnetic?

The correct order of increasing bond angle is:

Which of the following statements about hydrogen bonding is incorrect?

Calculate the bond order of $He_2^+$ ion.

Which of the following molecules is non-polar despite having polar covalent bonds?