Question

Write the merits of Mendeleev's periodic table.

Answer 1

A systematic arrangement of elements into groups and periods in the order of increasing atomic mass is called Mendeleev's periodic table.

The merits of Mendeleev's periodic table are as follows:

1. Prediction of undiscovered elements: Mendeleev predicted some elements should be discovered and they should occupy the space left in the periodic table. Mendeleev discovered eka-aluminium (Gallium ($\mathrm{Ga}$)) of group 13, eka-silicon (Germanium($\mathrm{Ge}$)) of group 14, eka-boron (Scandium ($\mathrm{Sc}$)) of group 15 of the modern periodic table.
2. Prediction of properties of undiscovered elements: Mendeleev predicted the properties of several elements that are yet to be discovered. The atomic mass and chemical properties of Gallium are very close to those predicted by Mendeleev.