Rutherford Scattering

Rutherford Scattering - Transcript

Nuclear Reactions
Rutherford s Alpha Scattering Experiment

CS 4 1 Describe how Rutherford showed that a The nucleus had a relatively small diameter compared with that of the atom b Most of the mass of the atom is concentrated in the nucleus

IN THE BEGINNING
In the early days of atomic theory many physicists tried to explain the model of an atom In 1902 Ernest Rutherford showed that alpha particles emitted from the decay of unstable radioactive materials were electrically charged helium nuclei travelling at high speed In 1909 Rutherford used alpha particles to investigate the composition of gold foil i e to explain the model of an atom

Aim
To investigate the composition of gold foil using alpha particles i e to explain the model of an atom

Apparatus
Rutherford s alpha scattering apparatus
vacuum

source



zinc sulphide detector gold foil

Procedure
Rutherford fired alpha particles through a piece of gold foil and used a zinc sulphide detector to detect the scattered alpha particles and their location

Results







































































































































































Results
Rutherford s experiment found that Most of the alpha particles passed through the gold foil undeviated A few alpha particles were deflected from their path but continued through the gold foil A small number of alpha particles rebounded

Conclusion
From the results of his experiment Rutherford explained As most alpha particles passed through the gold foil atoms undeviated Rutherford concluded that most of the atom was actually empty space The deviation of some alpha particles from their original path were due to positive charges within the foil

Conclusion
From the results of his experiment Rutherford explained A small number of alpha particles had rebounded because they collided with something much larger and heavier and which contains a concentrated region of positive charge

Conclusion
As a result of his observations Rutherford suggested that the atom had a positively charged centre which contained most of the mass He called the heavy positively charged centre the nucleus

He went on to suggest that the nucleus was surrounded by orbiting electrons required for electrical neutrality

Conclusion
As a result of his observations Rutherford suggested that the atom had a positively charged centre which contained most of the mass He called the heavy positively charged centre the nucleus

He went on to suggest that the nucleus was surrounded by orbiting electrons required for electrical neutrality

Conclusion
As a result of his observations Rutherford suggested that the atom had a positively charged centre which contained most of the mass He called the heavy positively charged centre the nucleus

He went on to suggest that the nucleus was surrounded by orbiting electrons required for electrical neutrality

Conclusion
As a result of his observations Rutherford suggested that the atom had a positively charged centre which contained most of the mass He called the heavy positively charged centre the nucleus

He went on to suggest that the nucleus was surrounded by orbiting electrons required for electrical neutrality

Conclusion
As a result of his observations Rutherford suggested that the atom had a positively charged centre which contained most of the mass He called the heavy positively charged centre the nucleus

He went on to suggest that the nucleus was surrounded by orbiting electrons required for electrical neutrality

Modern measurements show that the average nucleus has a radius in the order of 10 15 m This is 100 000 times smaller than the radius of a typical atom