Immediately before 1913, an atom was thought of as consisting of a tiny positively charged heavy core, called a nucleus, surrounded by light, planetary negative electrons revolving in circular orbits of arbitrary radii.

What Rutherford discovered was that most of the alpha particle "bullets" passed straight through the gold foil, as though it were empty space. The occasional particle was diverted from its course by something very small and dense in the gold atoms.

The Rutherford atomic model was also known as the "Rutherford nuclear atom" and the "Rutherford Planetary Model". In 1911, Rutherford described the atom as having a tiny, dense, and positively charged core called the nucleus. Rutherford established that the mass of the atom is concentrated in its nucleus. The light, negatively charged, electrons circulated around this nucleus, much like planets revolving around the Sun.

Rutherford's model varied from Dalton's and Thompson's models in that he considered that most of the atom was empty space, whereas in the earlier models the atom was considered solid.

From his own experiments and observations, as well as the work of his peers, Dalton proposed a new theory of the atom. This later became known as Dalton's atomic theory. The general tenets of this theory are as follows:

Dalton's atomic theory has been largely accepted by the scientific community, with the exception of three changes. We now know that (1) an atom can be further subdivided, (2) all atoms of an element are not identical in mass, and (3) using nuclear fission and fusion techniques, we can create or destroy atoms by changing them into other atoms.