Dalton's Atomic Theory
Fundamental Principles
John Dalton proposed the first systematic atomic theory in the early 1800s. His theory was based on experimental observations and provided a framework for understanding chemical reactions.
Carbon Monoxide (CO)
Carbon Dioxide (CO₂)
Key Postulates
- All matter is made up of indivisible atoms
- Atoms of the same element are identical
- Different elements have different types of atoms
- Atoms combine in whole number ratios to form compounds
- Chemical reactions involve rearrangement of atoms
Law of Constant Proportions
A pure compound always contains the same elements combined in the same proportion by mass, regardless of its source or method of preparation.
Law of Multiple Proportions
When two elements form multiple compounds, the ratio of the masses of the second element that combine with a fixed mass of the first element is always a small whole number ratio.
Historical Impact
Dalton's theory laid the groundwork for modern atomic theory and revolutionized our understanding of chemical reactions. His work bridged the gap between ancient Greek philosophical concepts and modern scientific understanding of atoms.