The Periodic Law states that the properties of elements are a periodic function of their atomic numbers. This means that when elements are arranged in order of increasing atomic number, their chemical and physical properties show a repeating pattern. This organization helps scientists predict the behavior of elements based on their position in the periodic table. The concept was first formulated by Dmitri Mendeleev in the 19th century, leading to the creation of the modern Periodic Table. The table organizes elements into rows and columns, where elements with similar properties are grouped together, making it easier to study and understand their relationships.