Here's why:
* Molecules are the fundamental building blocks of molecular compounds. They are formed when two or more atoms bond together chemically.
* Properties arise from the arrangement and interactions of atoms within a molecule. This includes things like melting point, boiling point, reactivity, and color.
* Individual atoms do not exhibit the same properties as the compound they form. For example, a single oxygen atom is very reactive, while a molecule of oxygen gas (O2) is relatively unreactive.
Example:
Water (H2O) is a molecular compound. A single molecule of water has the properties of water – it's a liquid at room temperature, it's transparent, it dissolves many substances, etc. You can't break down a water molecule further and still have the properties of water.
