- Chadwick is known for the Discovery of neutrons, so A corresponds to III.
- Rutherford is associated with the Nuclear atom model, as he proposed the nuclear model of the atom based on his gold foil experiment, so B corresponds to IV.
- Mosley worked on X-rays spectra, where he studied X-ray spectra and established Moseley’s law, so C corresponds to II.
- J. J. Thomson discovered Cathode rays, so D corresponds to I.
Thus, the correct matching is:
A-III, B-IV, C-II, D-I