What is the purpose of the periodic table?

The primary purpose of the periodic table is to organize elements based on their atomic number, which reflects the number of protons in each atom's nucleus. This organization allows for a systematic arrangement of elements, where elements with similar chemical properties are grouped together in the same columns or groups.

This arrangement reveals trends in properties such as electronegativity, ionization energy, and atomic radius, making it a valuable tool for predicting an element's behavior and characteristics. In addition to being organized by atomic number, the periodic table also categorizes elements as metals, nonmetals, and metalloids, further aiding in understanding their chemical reactivity and bonding behavior.

The other options do not accurately represent the main function of the periodic table. While it does help in predicting chemical reactivity to some extent, this is not its primary purpose. Instead, it focuses on the organization of elements, which serves as a foundation for chemistry.