Final answer:
The force of attraction between a positively charged portion of one molecule and a negatively charged portion of another molecule is the electromagnetic force, which is responsible for electrostatic interactions and connections like ionic bonding and hydrogen bonding. It is different from gravitational force, nuclear forces, and Van der Waals forces.
Step-by-step explanation:
The force of attraction between a positively charged portion of one molecule and a negatively charged portion of another molecule is the electromagnetic force.
The electromagnetic force is responsible for electrostatic interactions between charged particles. It plays a crucial role in molecular connections like ionic bonding and hydrogen bonding.
This force is different from the other options listed. Gravitational force is the force of attraction between objects with mass, while nuclear forces are involved in atomic nuclei and not between molecules, and Van der Waals forces are weaker forces that arise due to temporary dipole attractions between molecules with shared electrons.