1904 The Currant Bun

After Thomson had discovered the electron, he put forth the "currant bun" (also known as the "raisin bun") to illustrate the atomic structure.

Image...

The negative electrons were embedded in an atom like raisins in a loaf of bread. The "bread" had a positive charge and carried most of the mass. The "raisins" were much lighter and smaller. Thus the bread occupied almost all of the volume of the "bun".

The Bun is NOT Perfect

According to what was known at that time, this model was acceptable.
The crucial experiment which challenged this model was carried out by Geiger and Marsden under the direction of Ernest Rutherford a few years later. This experiment strongly supported the Rutherford model of the atom rather than Thomson's Currant Bun.

*back*

(C)1999 ThinkQuest Team 27954