The concept of the atomic number was not discovered by a single individual. It was developed and refined over time through the work of several scientists. The atomic number is a fundamental concept in the field of atomic theory, which has been studied and expanded upon by many scientists throughout history.
The modern understanding of the atomic number and its significance can be attributed to the work of Henry Moseley, an English physicist. In 1913, Moseley conducted experiments to investigate the X-ray spectra of various elements. Through his experiments, he discovered a relationship between the frequencies of X-ray emissions and the atomic numbers of elements. Moseley's work provided a more accurate and precise way to determine the ordering of elements in the periodic table based on their atomic numbers.
However, it is important to note that the development of the periodic table and the understanding of atomic numbers involved contributions from numerous scientists, including Dmitri Mendeleev, Julius Lothar Meyer, and others. The collective efforts of these scientists over many years led to the formulation and refinement of the concept of atomic numbers as we understand them today.