CHEM 1070 Chapter Notes - Chapter 9: Ion, Diamagnetism, Isoelectronicity
Document Summary
9-1 classifying the elements: the periodic law and the periodic table. Dmitri mendeleev and lothar meyer independently proposed the periodic law: when the elements are arranged in order of increasing atomic mass, certain sets of properties recur periodically. He left blank spaces in his table. Properties change gradually from top to bottom. Gallium, scandium, and germanium were found shortly after mendeleev"s death. Mendeleev did not anticipate the noble gases, so when william ramsay discovered them, he created an additional piece of the table for them. Atomic number as the basis for the periodic law. Some elements are out of order according to their atomic mass. Moseley reasoned that because the energies of electron orbitals depend on the nuclear charge, the frequencies of emitted x-rays should depend on the nuclear charges of atoms in the target. Similar properties recur periodically when elements are arranged according to increasing atomic number. Description of a modern periodic table: the long form.
