As seen, the electronic configuration of elements show a periodic dependence with increasing atomic number. Here we will examine how electronic configuration explains the periodic changing physical and chemical properties of elements. Originally will start with the notion of effective load nucleus.
Charge of the nucleus (Z) is simply the number of protons in the nucleus of an atom. Effective Charge of the nucleus (Zef) is the actual size of the positive load "experienced" by an electron in the atom. Because hydrogen has only one electron, is the only atom which loads the kernel and its effective loads are the same. In all other atoms, elcktmnet simultaneously withdrawn from the nucleus and pushed each other. This phenomenon is known as shade (defense). In atom with more electrons an electron is shaded (protected) from positive ngurkcsa börthames the other electrons in the atom.
