Question

describe the advantage and anomalies Mendeleev periodic table

Answer 1

Advantage-
1. Mendeleev's periodic law predicted the existence of some elements that had not been discovered at that time. E.g. Gallium, scandium and germanium.

2. Mendeleev's periodic table could predict the properties of several elements on the basis of their positions in the periodic table.

3. Mendeleev's periodic table could accommodate noble gases when they were discovered.

Anomalies -
1. The position of isotopes could not be explained.

2. Wrong order of atomic masses of some elements could not be explained. E.g. when put in correct group on the basis of chemical properties the element cobalt having higher atomic mass comes 1st n nickel with slightly lower atomic mass comes later.

3. A correct position could not be assigned to hydrogen in the periodic table.