The reaction described results in a molecule with two atoms of the same element that share six electrons. This indicates that the molecule is held together by a triple bond, which occurs when three pairs of electrons are shared between the two atoms.
Given the options:
A. Si2 - Silicon commonly forms covalent bonds but does not typically form triple bonds. B. F2 - Fluorine forms single bonds, sharing only two electrons. C. O2 - Oxygen forms a double bond, sharing four electrons. D. N2 - Nitrogen forms a triple bond, sharing six electrons.
Based on this information, the correct answer is D. N2.