John Dalton is often remembered for his important work in developing the idea of atoms, which is essential to modern science. However, he faced many challenges that made his work complicated.

1. Early Ideas and Limitations:

• Dalton said that everything is made of tiny, indivisible particles called atoms.
• He believed that each element had its own unique atoms with different weights.
• But later discoveries found smaller particles inside atoms, like protons, neutrons, and electrons.
• This showed that Dalton’s idea was too simple.

2. Problems with Dalton's Atomic Theory:

• The atomic mass values Dalton provided were not very accurate.
• This caused confusion when scientists tried to develop chemical formulas and understand chemical reactions.
• He also struggled to explain how gases behave and how different substances combine, leaving some important questions unanswered.

3. Impact on Chemistry:

• Dalton’s ideas helped lay the groundwork for chemistry, but they were not enough to explain more complex topics like isotopes (different versions of elements) and how molecules bond together.
• These concepts are a big part of modern chemistry.

4. Moving Forward:

• To fix these issues, chemists needed to build on Dalton’s ideas.
• They developed more detailed models to understand atomic structure better.
• Thanks to new technology, like quantum mechanics and better experiments, scientists have improved atomic theory by including the discoveries of smaller particles.

Even though John Dalton made significant contributions, the problems in atomic theory show that science is always changing. Continuous research and updates are essential in the field of chemistry.