feb 1, 1913 - Niels Bohr
Description:
Bohr created a new atomic model in 1913 that was the first model to incorporate a quantum theory. By observing light emitted by Hydrogen atoms, he devised that electrons are limited to a series of circular orbits around the nucleus. He proposed that light was emitted by hydrogen atoms only when an electron made a transition from an outer orbit to a closer one. He specified that the energy lost by the transition was the same amount as the quantum energy emitted by light.Added to timeline:
Date:
feb 1, 1913
Now
~ 113 years ago