Nitrogen bonding and electron affinity How does nitrogen bond with itself to form N2 if it has no affinity for electrons? If a nitrogen atom can't pull on the electrons of another nitrogen atom how can N2 have covalent bonds.
It doesn't matter that the electronegativity difference between nitrogen with itself is 0. It just means the bonds it makes with another nitrogen atom have $100~\%$ covalent character.

A typical chemical bond basically spans the spectrum of bonds with $100~\%$ ionic character, uneven ionic/covalent character, and $100~\%$ covalent character.


$\mathbf{100~\%}$ ionic character: $\ce{A^+B^-}$ or $\ce{A^- B^+}$, with no sharing of electrons at all
Uneven ionic/covalent character (i.e. polar): $\ce{{\stackrel{\delta+}{A}}-{\stackrel{\delta-}{B}}}$ or $\ce{{\stackrel{\delta-}{A}}-{\stackrel{\delta+}{B}}}$, with deviation from perfect sharing of electrons and direction of favored negative/positive end of dipole determined by electronegativity difference
$\mathbf{100~\%}$ covalent character (i.e. $100~\%$ nonpolar): $\ce{A-A}$ or $\ce{B-B}$, with perfect sharing of electrons


It just so happens that $\ce{N2}$ is one example of $100~\%$ covalent character. You can argue the same for $\ce{O2}$, and any similar homonuclear diatomic molecule. 

(Granted, there are some exceptions to 100% covalent character, like in iron's metallic bonding, but anyways...)