One atom loses an electron (becomes positively charged) and another atom gains that electron (becomes negatively charged).

This creates a strong electrostatic attraction between the two oppositely charged ions, holding them together.

Here's a breakdown:

* Metals tend to lose electrons, forming cations (positively charged ions).

* Nonmetals tend to gain electrons, forming anions (negatively charged ions).

Key characteristics of ionic bonding:

* High melting and boiling points: The strong electrostatic attraction between ions requires a lot of energy to break.

* Solid at room temperature: The strong forces hold the ions in a rigid, crystalline structure.

* Good conductors of electricity when dissolved or molten: The free movement of ions allows for the flow of electric current.

* Brittle: The rigid structure makes them susceptible to breaking when stressed.

Examples:

* NaCl (table salt): Sodium (Na) loses an electron to become Na+, and chlorine (Cl) gains that electron to become Cl-. The resulting ions are attracted to each other, forming an ionic bond.

* MgO (magnesium oxide): Magnesium (Mg) loses two electrons to become Mg2+, and oxygen (O) gains those two electrons to become O2-.