Photo: Niels Bohr's research notes for his new atomic ... give off energy and eventually spiral down into the nucleus, making the atom collapse. Or the electrons could be knocked out of position ...

Bohr began to work on the problem of the atom's structure. Ernest Rutherford had recently suggested the atom had a miniature, dense nucleus surrounded by a cloud of nearly weightless electrons.

Nobel prize-winning physicist Niels Bohr described these electrons in the atom as existing in a shell structure. The ...

he devised a quantum theory of the atom. In Bohr’s picture, the electrons encircling the atomic nucleus (that Rutherford had discovered in 1909) are constrained to specific orbits with quantized ...

When an electron dropped from a high-energy orbit to a lower-energy one, it gave out light with an energy equal to the ...

Bohr's 'solar system' model of the atom is the way that most people think ... pushed up to higher levels (at bigger distances from the nucleus). In time, they jump back down to a lower level ...