In what order does the periodic table list elements?

The periodic table organizes elements by atomic number, which corresponds to the number of protons found in the nucleus of an atom. This system of arrangement provides a clear progression, as the atomic number increases sequentially from one element to the next. This order reflects not only the identity of the element but also its position in the table, allowing for the grouping of elements that exhibit similar chemical properties.

This organization by atomic number leads to distinct patterns within the periodic table, such as trends in reactivity, electronegativity, and atomic radius. By listing elements in this manner, the periodic table serves as a functional tool for educators, chemists, and students, helping to facilitate understanding of elemental behavior and classification within the larger framework of chemical science.

While other methods like arrangement by atomic mass, reactivity, or density might seem relevant, they do not provide the same systematic and reliable structure as the atomic number arrangement, which is foundational in modern chemistry.