CLASS XII CHEMISTRY

ADVANTAGES OF MODERN PERIODIC TABLE

1. All elements in a group have same chemical properties and have same valencies.
2. A gradual change in the properties occurred along a period.
3. Molecular formula of elements can be predicted.
4. Chemical properties of elements can be predicted.
5. The exact location of an element in the periodic table can be predicted.

DISADVANTAGES OF MODERN PERIODIC TABLE

1. The exact position oh Hydrogen in a group is undecided.
2. Anomalous changes in thermodynamic values.
3. Certain chemically similar elements are placed in different groups.
4. In certain groups metals and non metals are produced.