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Notes

•Introduction Understanding the evolution of atomic models is essential in chemistry. From Dalton’s early idea of indivisible atoms to Schrödinger’s complex wave functions, each model has provided deeper insights into atomic behavior and interactions. These models form the foundation for understanding chemical reactions, bonding, and molecular structure. •Dalton's Atomic Theory John Dalton’s atomic theory (early 1800s) was the first to describe atoms as the fundamental building blocks of matter. His principles include: 1. Indivisibility of Atoms: All matter is made of tiny, indivisible particles called atoms. 2. Elemental Identity: Atoms of a specific element are identical in mass and properties, distinguishing them from other elements. 3. Simple Ratios in Compounds: Atoms combine in whole-number ratios to form compounds, explaining their composition. 4. Conservation in Reactions: Atoms rearrange during chemical reactions but are neither created nor destroyed, supporting the Law of Conservation of Mass. •Thomson's Plum Pudding Model J.J. Thomson’s discovery of the electron in the late 19th century led to a new atomic model: 1. Electrons in a Positive Matrix: Atoms...