Enumerate the properties and drawbacks of Mendeleev’s periodic table.

Mendeleev was the first person to organize the discovered elements in a systematic way.

Properties:

1. He arranged the elements in the increasing order of atomic mass. He observed that when doing so, the properties of elements repeated in regular intervals. Based on this, he made the Periodic Law: “The chemical and physical properties of the elements are periodic function of their atomic masses.”

2. The elements are arranged in horizontal rows called periods and vertical columns called groups. Each group contained 2 subgroups A and B. Each period was subdivided into series.

3. He left some gaps in periodic table, predicting the existence of certain elements like Gallium, Germanium and he also predicted their properties, which turned out to be true.

4. When noble gases were discovered, Mendeleev was able to put them in a new group, without affecting the existing periodic table.

Drawbacks:

1. Elements were not strictly arranged in the increasing order of atomic mass.

2. Certain elements with different properties were under the same group, and certain elements with same properties were under different groups.

3. Hydrogen did not have a fixed position in the periodic table.

4. The isotopes of the elements were given the same place in the table even though they had different atomic masses.