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Nitric oxide 
The nitric oxide (NO) molecule is composed of one atom of nitrogen and one atom of oxygen bound by a double bond. There are two pairs of non-bonding electrons on the oxygen atom and one pair of non-bonding electrons on the nitrogen atom (indicated by the yellow arrows). In addition an extra electron is present on the nitrogen (indicated by the red arrow), making this molecule a free radical. There are a total of 11 electrons in this structure. The more electronegative atom oxygen has 8 electrons in its outer shell while nitrogen has only 7 electrons in its outer shell. This extremely reactive free radical seeks to obtain another electron to fulfill the octet rule and become a lower energy species. 
Nitric oxide has a linear molecular shape. 
The electron pair geometry around both the oxygen and nitrogen atoms is trigonal planar. There are 3 groups of electrons around the nitrogen and the oxygen atoms (indicated by the red arrows). On the oxygen atom one group of electrons is represented by the double bond, the second group of electrons is represented by the unshared electron pair and the third group of electrons is also represented by the unshared electron pair. On the nitrogen atom one group of electrons is represented by the double bond, the second group of electrons is represented by the unshared electron pair and the third group of electrons is represented by the extra electron. 
This is the structural formula for nitric oxide. 
Nitric oxide has molecular polarity. The partial specific negative charge is on the oxygen atom and the partial specific positive charge is on the nitrogen atom. | |||||||||||