The term chemical structure refers to the arrangement and bonding of atoms, molecules or ions in a compound. It is the way the individual particles are connected together within a substance that determines its properties, reactivity and behavior. The specific order of elements in a compound's chemical formula represents the unique arrangement of these particles. Understanding the chemical structure of a substance can help chemists predict how it will behave, interact with other substances or be used for various applications such as drug development or materials science.