It's not quite accurate to say that "John atomic theory" is still mentioned in science. The correct term is Dalton's atomic theory, named after John Dalton, the English chemist who proposed it in the early 19th century.

While Dalton's atomic theory has been superseded by more advanced models of the atom, it's still mentioned in science for several reasons:

* Historical Significance: It marked a pivotal moment in the development of chemistry. It provided the first coherent and experimentally supported explanation for the nature of matter, laying the foundation for future advancements in atomic theory.

* Foundation for Modern Chemistry: Dalton's theory introduced key concepts that are still fundamental to our understanding of chemistry, such as:

* The existence of atoms: The idea that matter is composed of tiny, indivisible particles.

* The law of multiple proportions: How elements combine in fixed ratios to form compounds.

* The concept of atomic weight: The relative masses of atoms of different elements.

* Pedagogical Value: Dalton's theory is often introduced in introductory chemistry courses as a stepping stone to more complex atomic models. It provides a simplified framework that helps students grasp the basic principles of atomic structure and chemical bonding.

While Dalton's model of the atom is not entirely accurate (we now know that atoms are divisible into smaller subatomic particles), it remains a crucial piece of scientific history and provides a valuable context for understanding the evolution of our understanding of matter.