2.0 Modern Periodic Law & Modern Periodic Table

  Periodic Table

• Mosely proved that the square root of frequency $(?)$ of the rays, which are obtained from a metal on showering high velocity electrons which is proportional to the nuclear charge of the atom. This can be represented by the following expression.
  $\sqrt \upsilon = a(Z - b)$, where Z is nuclear charge on the atom, $a$ & $b$ are constants.
• The nuclear charge on atom is equal to the atomic number.
• According to modern periodic law, “the properties of elements are the periodic functions of their atomic numbers”.