History of Chemistry

The Greek Origins

• Democritus (400 BCE): Introduced the idea of indivisible particles called "atomos."
• Four Fundamental Substances: Ancient Greeks believed that all matter was composed of Fire, Earth, Water, and Air.

From Alchemy to Chemistry

During the Middle Ages, alchemists sought to transform base metals into gold and discover the "elixir of life." Their work laid the foundation for modern chemistry.

• Developed early techniques for distillation and filtration.
• Recorded observations systematically, leading to scientific methodologies.

The Scientific Revolution

• Robert Boyle (1661):
  • Established the scientific method in chemistry.
  • Defined an element as a substance that cannot be broken down further.
  • Proposed Boyle’s Law relating pressure and volume.
• Antoine Lavoisier (1774):
  • Proved the Law of Conservation of Mass: mass is neither created nor destroyed.
  • Disproved the phlogiston theory of combustion.
  • Named oxygen and hydrogen.

Dalton’s Atomic Theory

In 1808, John Dalton developed the first modern atomic theory:

• All matter is made up of atoms.
• Atoms of the same element are identical.
• Atoms combine in fixed ratios to form compounds.
• Atoms cannot be created or destroyed in chemical reactions.

Practice Questions

1. Who is considered the "Father of Modern Chemistry," and what are his contributions?
2. Explain the significance of the Law of Conservation of Mass.
3. How did Dalton’s Atomic Theory revolutionize the understanding of matter?