Question

Modern periodic table is based on atomic number of the elements. The significance of atomic number was proved by the experiment of:

• A. Discovery of X-ray by Roentgen
• B. Mulliken's oil drop experiment
• C. Bragg's work on X-ray diffraction
• D. Moseley's work on X-ray spectra

Answer 1

The correct option is D Moseley's work on X-ray spectra

Henry Moseley observed regularities in the characteristic X-ray spectra of the elements by plotting square root of frequency of x-rays against atomic number which gave a straight line. Thereby he showed that the atomic number is the most fundamental property of elements rather than atomic mass.

Hence, option D is correct.