Match the LIST-I with LIST-II
| LIST-I | LIST-II | ||
| (Scientist) | (Discovery/ Existence of) | ||
| A. | De Broglie | I. | Nucleus |
| B. | Rutherford | II. | Matter wave |
| C. | Thomson | III. | Neutron |
| D. | Chadwick | IV. | Electrons as constituents of atoms |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → A-II, B-I, C-IV, D-III
Each scientist is linked to the discovery that came from the experiment or hypothesis they are known for.
(A) De Broglie — this matches (II) Matter wave. De Broglie proposed that moving particles have a wavelength \( \lambda = h/p \) (matter waves).
(B) Rutherford — this matches (I) Nucleus. His alpha-scattering experiment showed that the positive charge and nearly all the mass are concentrated in a tiny nucleus.
(C) Thomson — this matches (IV) Electrons as constituents of atoms. J. J. Thomson measured \( e/m \) of cathode rays and established the electron as a constituent of all atoms.
(D) Chadwick — this matches (III) Neutron. Chadwick discovered the neutron in 1932.
NCERT (2026-27):
Summary – “… The waves associated with the moving material particles are called matter waves or de Broglie waves.”
Introduction – “… In 1897, the experiments on electric discharge through gases carried out by the English physicist J. J. Thomson (1856 – 1940) revealed that atoms of different elements contain negatively charged constituents (electrons) that are identical for all atoms.”
Alpha-particle Scattering and Rutherford’s Nuclear Model of Atom – “… This is why Rutherford is credited with the discovery of the nucleus.”
Atomic Masses and Composition of Nucleus – “… Chadwick was awarded the 1935 Nobel Prize in Physics for his discovery of the neutron.”