Explanation:

Dalton's Atomic theory was proposed in the early 1800s and was a significant step forward in understanding the nature of matter. However, it had some limitations and could not explain some of the phenomena observed later. One of the following phenomena that Dalton's atomic theory could not explain is the discovery of sub-atomic particles.

Discovery of sub-atomic particles:

The discovery of sub-atomic particles such as electrons, protons, and neutrons challenged Dalton's atomic theory. These particles were discovered later in the 19th and early 20th centuries, after the formulation of Dalton's atomic theory. These particles are smaller than atoms and play an essential role in the behavior of matter. The properties of these particles affect the chemical and physical properties of atoms and molecules, which are the building blocks of matter.

Limitations of Dalton's atomic theory:

Dalton's atomic theory had some limitations, which were later overcome by the discovery of sub-atomic particles. Some of the limitations of Dalton's atomic theory are:

1. It assumed that all atoms of the same element are identical, which is not always true.

2. It assumed that atoms are indivisible, which is not true as atoms can be broken down into sub-atomic particles.

3. It could not explain the periodic trends observed in the properties of elements.

Conclusion:

In conclusion, Dalton's atomic theory was a significant step forward in understanding the nature of matter, but it had some limitations. The discovery of sub-atomic particles challenged Dalton's atomic theory and led to the development of modern atomic theory. The modern atomic theory explains the behavior of matter based on the properties of sub-atomic particles.

Because, according to Dalton, atom is the Smallest indivisible particle of matter which was proved wrong later.... hence he cannot explain about sub-atomic particles like electrons, protons and neutrons.