Which one of the following is not explained by the Dalton's atomic theory ?

John Dalton's atomic theory, proposed in 1808, was built upon the fundamental laws of chemical combination. It successfully explained the Law of Conservation of Mass by stating that atoms are indivisible and cannot be created or destroyed in chemical reactions [2]. It also accounted for the Law of Constant Composition (Definite Proportions) and the Law of Multiple Proportions by postulating that atoms of different elements combine in simple, fixed whole-number ratios to form compounds [2]. However, Dalton's theory regarded the atom as the ultimate, indivisible particle of matter [1]. It failed to explain the presence of sub-atomic particles like electrons, protons, and neutrons, which were discovered later through experiments involving electricity and radioactivity [1]. These discoveries eventually proved that atoms are not indivisible but possess a complex internal structure, a concept that Dalton's original theory did not encompass [1].

Sources

1. [2] https://www.khanacademy.org/science/class-11-chemistry-india/xfbb6cb8fc2bd00c8:in-in-some-basic/xfbb6cb8fc2bd00c8:in-in-law-of-chemical-combination/a/daltons-atomic-theory-version-2
2. [1] https://ncert.nic.in/textbook/pdf/kech102.pdf