Question

Statement 1: Mendeleev's periodic law states that the properties of elements are the periodic function of their atomic mass.

Statement 2: The modern periodic law states that the properties of elements are the periodic function of their atomic number.

• A. Statement 1 is true but statement 2 is false.
• B. Both statement 1 and statement 2 are true.
• C. Both statement 1 and statement 2 are false.
• D. Statement 1 is false and statement 2 is true.

Answer 1

The correct option is B Both statement 1 and statement 2 are true.

Mendeleev arranged elements according to their atomic masses and stated that the properties of elements are the periodic function of their atomic mass.
Moseley arranged them according to their atomic number and gave the modern periodic law which states that the properties of elements are the periodic function of their atomic numbers.