The key difference between Mendeleev and modern periodic table is that Mendeleev’s periodic table was based on the increasing atomic masses while the modern periodic table is based on the increasing atomic numbers. Let us see here what is Mendeleev periodic table and what is modern periodic table, and then compare both to understand the difference between both periodic tables. Mendeleev is the pioneer of the modern periodic table, though a numerous number of changes had been made to the old version of the periodic table. Both of these attempts are equally important to the scientific community; because without an invention of the periodic relationship in elements, the modern developments in Science would not reach a development era as today. Before the invention of Mendeleev’s classification, there were several attempts made by several chemists, but their periodic laws were inadequate to apply for all the elements. The modern periodic table is so advantageous for the development in the Science.
The number next to the simbol of the element ions (as a superscript) means the number of charges of the ion. For example N (+),, where (+) is a superscript means that the charge of the ion is 1+. S(2-), where (2-) is a superscript, means that the charge of the ion is (2-). OH (-), where (-) is a superscript, means that the charge of OH ion is (1-) .
The atomic number of Ga is 31. The electronic configuration for the neutral atom at ground state is; 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p¹ Once it becomes a cation after losing three electrons, the electronic configuration of Ga³⁺ is; 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ The outermost shell in the neutral atom was the 4th energy shell. But after losing the three electrons, the outermost shell is the 3rd energy shell. the number of electrons in the 3rd shell are - 2 + 6+ 10 = 18 There are 18 electrons in the outermost shell of Ga³⁺.
"between energy, electron position and the emission of electromagnetic energy. However, it is ... From that excitation state, the electron can then drop back down, releasing a photon with a predictable amount of energyin the process."