History of the atom timeline
- The atomic model developed by scientists has changed over time as experimental evidence has improved our understanding of the structure of atoms
- In 1803, John Dalton presented his atomic theory based on three key ideas:
- Matter is made of atoms which are tiny particles that cannot be created, destroyed, or divided
- Atoms of the same element are identical, and atoms of different elements are different
- Different atoms combine together to form new substances
- At the time, the theory was correct but as science developed some parts of Dalton's theory were disproved
- This is a fundamental feature of science: new experimental evidence may lead to a scientific model being changed or replaced
The evolution of models of atomic structure