What is the basic difference in approach between mendeeleev's periodic low and modern periodic low​...

Answer:

Mendeleev stated that the properties of the elements are a periodic functions of their atomic weight.

The modern periodic law states that the physical and chemical properties of the elements are periodic functions of their atomic numbers.

So, Mendeleev's periodic law is based upon the atomic weights of elements whereas modern periodic law is based upon atomic number of elements.

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