# Lesson 3.4 - Covalent Bonding

## Forming covalent bonds

Covalent bonds are formed when atoms *share* electrons.

They occur between *non-metals*.

## Forces

The forces *between atoms* are very strong.

In **simple covalent structures**, the **intermolecular** forces are weak. This gives these structures low melting and boiling points.

In **giant covalent structures**, the intermolecular forces are very strong. This makes these substances harder, with a higher melting and boiling point.

## Polymers

Polymers are very large, covalent molecules.

They are made by joining together many **monomers** in a 'chain'.

## Giant covalent structures

Giant covalent structures are very strong.

Some examples include:

* Diamond
* Silicon dioxide (sand)
* Graphene

## Representing covalent bonds

We can represent covalent bonds using a:

* Dot and cross diagram
* Ball and stick model
* 2D diagram
* 3D diagram

> Note that these diagrams are the same as in *ionic* compounds - they're very useful for many things!
