Final answer:
Nitrogen (N) has three unpaired electrons.
Step-by-step explanation:
Out of the given options, the atom with three unpaired electrons is Nitrogen (N).
Nitrogen has five valence electrons, represented in a Lewis symbol as N. This symbol indicates three unpaired electrons and one electron pair. The unpaired electrons can form covalent bonds, while the paired electrons remain as a lone pair on Nitrogen in its compounds.
Therefore, the correct answer is c. N.