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What are alpha-particles (α-particles)? Describe the experiment carried out by Rutherford and his co-workers that led to the discovery of the nucleus - Leaving Cert Chemistry - Question b - 2002
Question b
What are alpha-particles (α-particles)? Describe the experiment carried out by Rutherford and his co-workers that led to the discovery of the nucleus. Explain how R... show full transcript
Worked Solution & Example Answer:What are alpha-particles (α-particles)? Describe the experiment carried out by Rutherford and his co-workers that led to the discovery of the nucleus - Leaving Cert Chemistry - Question b - 2002
Step 1
Step 2
Describe the experiment carried out by Rutherford and his co-workers that led to the discovery of the nucleus.
Answer
Rutherford and his team conducted an experiment in which they bombarded a very thin foil of gold with alpha-particles. They used a zinc sulfide detector to observe the pattern of scattering of these alpha-particles.
Most of the alpha-particles passed straight through the foil, indicating that the majority of the atom is empty space. However, some particles were deflected at large angles, and a few were even reflected back, suggesting the presence of a concentrated center within the atom.
Step 3
Explain how Rutherford interpreted the results of this experiment to conclude that the atom has a nucleus.
Answer
Rutherford interpreted these results as indicative of a small, dense, positively charged nucleus at the center of the atom. The observations can be explained by proposing that:
- The majority of the mass of the atom is concentrated in a small space within the nucleus.
- The positive charge is also concentrated in this small area, repelling the nearby alpha-particles, which leads to their deflection.
- The large amount of empty space surrounding the nucleus allows most alpha-particles to pass through without any deflection.