Question

What is the principle behind the construction of long form of periodic table?

• A. Atomic mass
• B. Atomic number
• C. Atomic size
• D. Metallic & non-metallic character

Answer 1

The correct option is B

Atomic number

In 1913, an English physicist Henry Moseley discovered that chemical properties of elements depend upon the nuclear charge of the elements. Hence the Modern periodic law was proposed stating that the properties of the elements are periodic functions of the atomic number (nuclear charge).