Final answer:
MgCl2, exhibiting high conductivity, is characterized by ionic bonding due to the movement of ions in a dissolved or molten state.
Step-by-step explanation:
The compound MgCl2 is most likely to exhibit ionic bonding. Its high conductivity, as indicated by the bright illumination of red and green lights on a conductivity meter, points towards the presence of freely moving charged particles. In the case of MgCl2, these are ions, which are able to move when the compound is dissolved in water or molten, allowing it to conduct electricity effectively. The combination of a metal (Mg) and a nonmetal (Cl) typically forms an ionic compound, as metals tend to lose electrons to nonmetals, creating positively charged metal ions and negatively charged nonmetal ions that are held together by electrostatic forces in a crystalline lattice.