What was John Dalton's atomic model?

John Dalton's atomic model proposed that matter is composed of small, indivisible particles called atoms.

John Dalton, an English chemist and physicist, introduced his atomic theory in the early 19th century. His model was groundbreaking at the time and laid the foundation for modern chemistry. Dalton suggested that all matter is made up of tiny, indivisible particles called atoms, which cannot be created or destroyed. He believed that atoms of a given element are identical in mass and properties, while atoms of different elements have different masses and properties.

Dalton's atomic model also proposed that chemical reactions involve the rearrangement of these atoms. He theorised that compounds are formed when atoms of different elements combine in fixed, simple whole-number ratios. For example, water (H₂O) is formed when two hydrogen atoms combine with one oxygen atom. This idea helped explain the law of definite proportions, which states that a chemical compound always contains the same elements in the same proportions by mass.

Dalton's model was based on experimental evidence and observations, such as the behaviour of gases and the laws of chemical combination. Although his model was later refined and expanded upon by other scientists, it was a crucial step in the development of atomic theory. Dalton's work provided a systematic way to understand the composition and behaviour of matter, paving the way for future discoveries in chemistry and physics.