Question
In an experiment, a beam of alpha particles was directed at a thin sheet of gold foil. Most of the alpha particles passed straight through the gold foil. Alpha particles which passed close to the nucleus of a gold atom did not pass straight through. What happened to the alpha particles which passed close to the nucleus of a gold atom? [1 mark]
Answer
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Timothy
Elite · Tutor for 8 years
Answer
The alpha particles which passed close to the nucleus were deflected away at varying angles due to the repulsion from the positive charge concentrated within the tiny nucleus. Some could have also been absorbed by the nucleus.
Explanation
## Step 1: Understand the given questionThe problem refers to the gold foil experiment by Rutherford, similar to one mentioned in the example. Most of the alpha particles passed straight through the gold foil, indicating that they encountered no, or negligible, forces, affirming the idea of 'empty space' within atoms. This is a basic tenet of the atomic model where the positive charge (around which alpha particles revolve) is placed in the atom's center. ## Step 2: Interpret the experimental setting However, some alpha particles which passed close to the gold atom's nucleus did not pass straight through. These are instances where alpha particles encounter a repulsive force, attributed to the presence of a densely packed, positively charged mass; the nucleus. ## Step 3: Draw logical conclusionGiven these pieces of information mentioned in points 1 and 2, the feasible explanation remains that; when close to the nucleus, alpha particles are either repelled (deflected away at varying angles), due to the force exerted by the positive charge within the nucleus, or absorbed by the nucleus itself.