Question

State the modern periodic law.
Who devised a new method of classifying elemetns?

Answer 1

The Modern Periodic Law states that :

The Elements are the periodic function of their atomic numbers.

Henry Moseley proposed to classify the elements according to their atomic numbers. He considered it as more fundamental property than atomic mass

Hope this helps you!

Answer 2

Henry Moseley put forward the Modern Periodic Law.

The modern Periodic Law states that the properties of elements are the periodic functions of their atomic number
i,e.
if the elements are arranged in tabular form in the increasing order their atomic numbers,then the properties of the elements are repeated after definite regular intervals or periods.

After that Neil Bohr gave the extended form of the long or modern periodic table in the picture above.