Question

Who discovered atomic numbers and by which study?

Answer 1

Atomic number is the number of protons in the nucleus of each atom of that element. An atom can be classified exclusively on the basis of its atomic number.

Complete step by step solution:
An atomic number is the number or protons present in the nucleus. For example- an atom having an atomic number of eight means that the element has 8 protons in the nucleus is an atom of oxygen. The periodic table is arranged in the increasing order of atomic numbers. Since the atoms are neutral the number of protons is equal to the number of electrons, so when an atom is neutral the atomic number can be defined as the number of electrons present around the nucleus of each atom of that element. Atomic number was discovered by Henry Moseley in the year 1913 by the study of the X- ray spectra. He found that certain lines in the x-ray spectrum of elements move to the same amount each time when we increase the atomic number by one.

Note: The importance of atomic number is that it helps in the identification of the selected element of an atom. The arrangements of the elements in many models of periodic table is done on the basis of the atomic number. The elements are set in increasing order of the atomic numbers of the elements. Atomic number also helps us to define the properties of an element, it tells us about the number of protons present in the nucleus of that atom.