Question

The first periodic law stated by Mendeleev was:
(A) there is no correlation in the properties and atomic weights of the elements
(B) the properties of the elements are a periodic function of their atomic weights
(C) the properties of elements are a periodic function of their atomic weights
(D) the properties of the elements are a periodic function of their empirical formula

Answer 1

Hint: Genesis of periodic classification of elements into groups and development of periodic law and the periodic table. It is very necessary to classify elements to study the individual properties and a systemic way to organize their knowledge in searching elements. Mendeleev proposed his own periodic law that when the elements are arranged in order to increase atomic mass, certain sets of properties recur periodically. This periodic law introduced atomic volume as the ratio of atomic mass of an element to the density of the solid form.

Complete step by step solution:
Firstly Doberneir started the study of a periodic relationship after that Mendeleev was responsible for the first time-periodic table constructed and published the first periodic law as follows:
“The properties of the elements are a periodic function of their atomic weights” -- (1)
After that Mendeleev’s modified periodic law which identifies atomic number is more fundamental property than atomic mass and the modifies periodic law is named as Modern periodic law which states as follow:
“The physical and chemical properties of the elements are periodic functions of their atomic numbers” --- (2)
This law modifies the Mendeleev’s periodic table into the modern periodic table.
The statement (1) is related to the first periodic law by Mendeleev.


Hence, the correct statement is option B.


Note: Coinage metals like copper, silver, and gold are grouped in Mendeleev’s periodic table and manganese metal is also allotted in the halogen group. These defects are resolved by the modern periodic table. The fundamental property to distinguish each element in the modern periodic table is the atomic number which gives basic nature to decide the physical and chemical properties of elements than atomic weights.