* Like charges repel: Chlorine ions (Cl-) are negatively charged. Like charges repel each other, so two chlorine ions would push away from each other.

* Ionic Bonding: To form a molecule, atoms must share electrons (covalent bonding) or transfer electrons (ionic bonding). In ionic bonding, a metal atom loses electrons to become a positively charged cation, and a non-metal atom gains electrons to become a negatively charged anion. The opposite charges attract, forming an ionic compound.

To form a molecule, you would need:

* A positive and a negative ion: A chlorine ion (Cl-) would need a positively charged ion to form a bond. This could be a metal ion like sodium (Na+), forming sodium chloride (NaCl).

Let me know if you'd like to explore other examples of ionic compounds!