<P> After Rutherford's discovery, scientists started to realize that the atom is not ultimately a single particle, but is made up of far smaller subatomic particles . Subsequent research determined the exact atomic structure which led to Rutherford's gold foil experiment . Scientists eventually discovered that atoms have a positively charged nucleus (with an exact atomic number of charges) in the center, with a radius of about 1.2 × 10 meters × (Atomic Mass Number). Electrons were found to be even smaller . </P> <P> Later, scientists found the expected number of electrons (the same as the atomic number) in an atom by using X-rays . When an X-ray passes through an atom, some of it is scattered while the rest passes through the atom . Since the X-ray loses its intensity primarily due to scattering at electrons, by noting the rate of decrease in X-ray intensity, the number of electrons contained in an atom can be accurately estimated . </P> <P> See also Bohr model, which applies just as well to the section below . </P> <P> Rutherford's model deferred to the idea of many electrons in rings, per Nagaoka . However, once Niels Bohr modified this view into a picture of just a few planet - like electrons for light atoms, the Rutherford - Bohr model caught the imagination of the public . It has since continually been used as a symbol for atoms and even for "atomic" energy (even though this is more properly considered nuclear energy). Examples of its use over the past century include but are not limited to: </P>

According to the rutherford model of the atom the positive charge is