Moseley’s law

Moseley's law, established by physicist Henry Moseley, revolutionized the understanding of atomic structure. It experimentally demonstrated that an element's properties are determined by its atomic number, rather than its atomic weight. Moseley studied X-ray spectra emitted by elements and found a direct relationship between the frequencies of these X-rays and the atomic number. Specifically, he showed that the frequency of an X-ray line is proportional to the square of the atomic number. This discovery firmly linked the atomic number to the positive charge within the atomic nucleus and provided a more accurate ordering of elements in the periodic table.12