Photo: Niels Bohr's research notes for his new atomic theory Rutherford's find came from a very strange experience. Everyone at that time imagined the atom as a "plum pudding." That is ...

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.

So convincing is this model that after only twelve years it is known no longer as “the atomic model of Rutherford and Bohr,” but is simply taken for granted as “the atom.” In this ...