In this deck, we'll explore one of the most important ideas in chemistry: how the way particles are bonded and arranged determines a substance's properties. We'll look at why salt has a high melting point, why oxygen is a gas at room temperature, and why metals can be shaped and conduct electricity. By the end, you'll be able to explain the properties of ionic compounds, simple molecules, giant covalent structures, and metals.

Let's start with ionic compounds, like sodium chloride, or table salt. These compounds form a structure called a giant ionic lattice. This is a regular, repeating arrangement of positive and negative ions, held together by very strong electrostatic forces of attraction acting in all directions.

Because these electrostatic forces are so strong, it takes a great deal of energy to overcome them and break the ions apart. This is why ionic compounds have very high melting points and boiling points. They are solids at room temperature because a huge amount of heat energy is needed to separate the ions.