Image Caption
In the early 1900s, Ernest Rutherford and his colleagues performed this experiment to test the hypothesis that an atom's mass and positive charge are spread diffusely throughout the atom and found that their expectations and actual observations did not match at all.
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This image is part of a series:
![Three images in succession detailing Rutherfords hypothesis. First the hypothesis shows a hydrogen atom. Next the expectation is that some alpha particles bounce back the way they come when sprayed into a gold foil. Last, the actual result shows some alpha particles bounce back the way they came.](https://undsci.berkeley.edu/wp-content/uploads/2022/08/34227_evo_resources_resource_image_59_original-350x238.gif)