1913Reputable sourceWell documented
Bohr's Quantum Atom
On the timeline · around 1913 ·
What happened
In 1913 the Danish physicist Niels Bohr fused Rutherford's nuclear atom with Planck's quanta. He proposed that electrons can orbit the nucleus only in certain fixed energy levels, jumping between them by absorbing or emitting a quantum of light — which explained, at last, the precise colours of light emitted by hydrogen.
Why it matters
Bohr's model was the first successful quantum theory of the atom, tying the structure of matter to the quantum. It launched the decade of discovery that produced full quantum mechanics.