What term refers to the systematic manner in which the physical and chemical properties of elements occur based on atomic number?

The term that refers to the systematic manner in which the physical and chemical properties of elements occur based on atomic number is known as the periodic law. This concept was first established by Dmitri Mendeleev and later refined, stating that the properties of elements tend to recur at regular intervals when they are arranged by increasing atomic number. This means that elements with similar properties appear at regular intervals in the periodic table, leading to the organization of the table we use today.

The periodic law highlights the relationship between an element's atomic number and its properties, making it a foundational principle in understanding the behavior of elements. This aspect is crucial for predicting the characteristics of unknown elements and studying trends in the periodic table, such as electronegativity, ionization energy, and atomic radius.

The other terms, while related to chemistry, do not specifically address the relationship between atomic number and properties in a patterned manner. Periodic behavior might refer broadly to characteristics that repeat but lacks the precise definition provided by the periodic law. The chemical principle is a vague term that could mean many things in chemistry, and atomic theory primarily deals with the nature of atoms and their interactions. Thus, the periodic law is the most accurate representation of the systematic trends observed in elemental properties according