Atoms that share electrons in their outer shell are called covalent bonds. This type of bonding occurs between nonmetals and is characterized by the sharing of electrons between the atoms involved.

Here's a breakdown:

* Outer Shell (Valence Shell): The outermost electron shell of an atom.

* Electrons: Negatively charged particles that orbit the nucleus of an atom.

* Sharing: When two atoms share electrons, they create a stable arrangement where both atoms have a full outer shell, mimicking the noble gas configuration.

Examples of Covalent Bonds:

* Water (H2O): The oxygen atom shares two electrons with two hydrogen atoms.

* Carbon Dioxide (CO2): The carbon atom shares four electrons with two oxygen atoms.

* Methane (CH4): The carbon atom shares four electrons with four hydrogen atoms.

Key Points:

* Covalent bonds are typically stronger than ionic bonds (where electrons are transferred).

* They can be single, double, or triple bonds, depending on the number of electrons shared.

* Covalent bonds are responsible for the formation of a vast majority of organic molecules, including those found in living organisms.

Let me know if you'd like more examples or details about covalent bonding!