Prof.dr Ing. J.F.J van den Brand, Sep. 2006  – 8
De structuur van atomen
Rutherford (1912) toonde aan dat atomen een centrale kern bevatten
Elektronen draaien rond de kern met precies gedefinieerde energie en slecht gedefinieerde posities
10-10 m
However it was in 1912 that the New Zealander Ernest Rutherford gave us our modern view of the atom when he showed that atoms have a positive nucleus surrounded at a relatively large distance by the electrons, a picture that everyone today recognizes as the symbol for the atom.
The photograph shows Rutherford in his lab. The sign says ‘Talk softly please’ supposedly put there because the detectors were sensitive to noise. However the more likely explanation is that it was aimed at Rutherford by his colleagues, since he was renowned for his booming voice.
Now it became clear what differentiates the elements - the number of electrons and the charge on the nucleus - for example hydrogen has one electron, helium has two, carbon six, lead eighty-two etc.
However the story doesn’t stop there.