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A Theory of sound:
as vibrations in an elastic medium is propounded by British physicist John Rayleigh -
Radioactivity is discovered:
By French physicist Antoine Becquerel -
Diffraction in X-rays:
German Physicist Max Von Laue produces diffraction in X-rays by passing them through crystals, showing that X rays are electromagnetic waves -
Quantum Theory
Danish physicist Niels Bohr develops the quantum theory of the hydrogen atom -
Theory of Relativity:
Albert Einstein develops his general theory of relativity, incorporating gravitation and acceleration into the theory and developing the notion of the space-time continuum -
The Existence of the Proton:
Ernest Rutherford demonstrates the existence of the proton, the particle in the atomic nucleus carrying a positive charge (1916) -
Electrons can behave as Waves
French physicist Louis De Broglie finds, by combining quantum theory with Einstein’s mass – energy equation, that electrons can behave as waves -
Wave Mechanics
German physicist Erwin Schrödinger develops de Broglie’s ideas into a complete theory of subatomic behaviour, called wave mechanics. -
The discovery of the Neutron:
Made by British physicist James Chadwick.The following year American physicist Carl Anderson discovers the Positron -
The Neutrino:
An elementary particle, is discovered by American physicists Clyde Woman and Fred Reins -
Evidence of the existence of W and Z Particles
This is confirmed at CERN, the European particle physics laboratory, establishing the link between the weak nuclear force and the electromagnetic force. (1983)