Question

Modern periodic law was proposed by:
A. Mendeleev
B. Henry Moseley
C. Werner
D. Bohr & Bury

Answer 1

Hint: The Scientist who invented modern periodic law was an English physicist. Elements arranged in the periodic table are the periodic function of their atomic number.

Complete step by step solution:
The periodic table is an arrangement of the chemical elements, organized on the basis of their atomic numbers, electron configurations and recurring chemical properties. Elements are presented in order of increasing atomic number. The standard form of the table consists of a grid with rows called periods and columns called groups.
Dmitri Ivanovich Mendeleev proposed the periodic law behind his periodic table compiling. This law states that when the elements are listed in order of increasing atomic weights, their properties vary periodically. That is, similar elements do not have similar atomic weights. Rather, as we go down a list of elements in order of atomic weights, corresponding properties are observed at regular intervals.
It was Henry Moseley who suggested a better arrangement than Mendeleev. He arranged the elements according to their Atomic Number rather than their Atomic mass. By doing so he improved upon the previous table and removed some of its difficulties and anomalies.
The modern Periodic law can be stated as: “The physical and chemical properties of the elements are periodic functions of their atomic numbers”. The atomic number is equal to the number of electrons or protons in a neutral atom.”
Therefore, the correct option is (b) Henry Moseley.

Note: Werner’s Theory is applicable for coordination compounds and Bohr & Bury explains the distribution of electrons in different orbits or shells.