Chemistry Discoveries, Periodic Table & Elements
The evolution of modern chemistry transformed alchemy into an exact quantitative science. Antoine Lavoisier established the Law of Conservation of Mass in 1789, disproving the phlogiston theory and correctly identifying oxygen's role in combustion. In 1869, Russian chemist Dmitri Mendeleev published the Periodic Table of elements, arranging elements by atomic mass and successfully predicting the properties of undiscovered elements such as gallium and germanium. Henry Moseley reorganized the periodic table in 1913 based on atomic numbers ($Z$). Marie Curie and Pierre Curie discovered the radioactive elements polonium and radium in 1898, pioneering the field of radioactivity, while Linus Pauling elucidated the nature of the chemical bond in 1939.
Key Concepts & Examination Highlights
- Dmitri Mendeleev published the first widely recognized Periodic Table in 1869, arranging elements by periodic trends and predicting unknown elements.
- Antoine Lavoisier is regarded as the father of modern chemistry for establishing the Law of Conservation of Mass and naming oxygen and hydrogen.
- Marie Curie remains the only person to receive Nobel Prizes in two distinct scientific disciplines: Physics (1903) and Chemistry (1911).