Question

how do ionic bonds form? atoms donate electrons to a \sea\ of electrons. atoms share electrons to fill their valence shell. atoms gain or lose electrons to fill their valence shell.

Explanation:

To determine how ionic bonds form, we analyze each option:

• The first option describes metallic bonding (electrons in a "sea"), not ionic bonding.
• The second option describes covalent bonding (sharing electrons).
• Ionic bonds form when atoms (usually a metal and a non - metal) gain or lose electrons to achieve a full valence shell, resulting in the formation of ions that are attracted to each other. So the third option is correct.

Answer:

The third option: Atoms gain or lose electrons to fill their valence shell.