Why is NO paramagnetic in gaseous state but diamagnetic in solid and liquid state?

The number of electrons in Nitrogen are 7 and in oxygen are 8. Hence the number of electrons that would be present in the molecular orbitals in NO are 7 + 8 = 15. As the number of electrons are odd, all the electrons in NO molecule cannot be paired. Hence, a single electron would be present in a π*2p orbital. Therefore NO is an odd electron species and the gas is hence paramagnetic due to the presence of unpaired electron. In the liquid and the solid state, the gas dimerises. The unpaired electron becomes paired and NO is therefore diamagnetic. 

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