Rutherford's scattering experiment
Rutherford did the experiment to make the conclusions about the model of the atom. Today, lets see deep into it.
Experiment:
The following set up was created.
1.He used a radioactive substance which usually emit alpha(α) particle(He²⁺)[positively charged].
2.Alpha particle could scatter easily. So, he used a lead slit to converge it and make a beam of alpha particle.
3. Then, the beam of alpha particle hit the thin gold foil.
4. The gold foil is surrounded by ZnS screen as shown in the diagram. ZnS is used to show the scintillation when alpha particles hit it.
Observation:
1. Most of the particle moves straight after passing the gold foil and hit the ZnS screen.
2. Some deflected at larger and smaller angle as shown in the diagram.
3. Only very few(like 1 in 20000) deflected back.
Conclusion:
We know that gold foil contain atoms in it. According to J. J Thomson's model, atom is positive sphere with negative electrons in it. So when alpha particles[positively charged particles] hit the positive sphere, it must repel and most of alpha rays should have been deflected back, but that didn't happen. Instead, most of the alpha rays passed through the gold foil and moved straight towards the ZnS screen.
1. So, Rutherford concluded that most of the space in the atom is empty.
Rutherford observed that some deflected at larger angle and some at shorter angle.
2. Thus, he concluded that atoms have positively charged dense sphere at it centre(nucleus)
Only very few(like 1 in 20000) deflected back. When alpha particles[positively charged particles] hit the nucleus[positively charged particle], it must repel. He said that very few alpha rays deflected back because the nucleus was so smaller than atom.
3. The size of nucleus is smaller.
2. Some deflected at larger and smaller angle as shown in the diagram.
3. Only very few(like 1 in 20000) deflected back.
Conclusion:
We know that gold foil contain atoms in it. According to J. J Thomson's model, atom is positive sphere with negative electrons in it. So when alpha particles[positively charged particles] hit the positive sphere, it must repel and most of alpha rays should have been deflected back, but that didn't happen. Instead, most of the alpha rays passed through the gold foil and moved straight towards the ZnS screen.
1. So, Rutherford concluded that most of the space in the atom is empty.
Rutherford observed that some deflected at larger angle and some at shorter angle.
2. Thus, he concluded that atoms have positively charged dense sphere at it centre(nucleus)
Only very few(like 1 in 20000) deflected back. When alpha particles[positively charged particles] hit the nucleus[positively charged particle], it must repel. He said that very few alpha rays deflected back because the nucleus was so smaller than atom.
3. The size of nucleus is smaller.
