| Method |
Precise Learning Objective |
Linked |
Question / Activity
(Designed for maximum working out) |
Stepping Stones |
Pitstop Check
(Thinking Map) |
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New experimental evidence may lead to a scientific model being changed or replaced.
(WS) This historical context provides an opportunity for students to show an understanding of why and describe how scientific methods and theories develop over time. |
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What can lead to a scientific model being changed or replace? |
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Before the discovery of the electron, atoms were thought to be tiny spheres that could not be divided. |
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What is an atom? |
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The discovery of the electron led to the plum pudding model of the atom. |
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What were the main features of the 'plum pudding' model of the atom? EW: Explain the events and discoveries that led to our understanding of the structure of the atom today. |
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The plum pudding model suggested that the atom is a ball of positive charge with negative electrons embedded in it. |
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How did the 'plum pudding' model describe the structure of an atom? |
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The results from the alpha particle scattering experiment led to the conclusion that the mass of an atom was concentrated at the centre (nucleus) and that the nucleus was charged. This nuclear model replaced the plum pudding model. |
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How did the Rutherford's alpha particle scattering experiment change our understanding of the structure of the atom? element card sort |
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Niels Bohr adapted the nuclear model by suggesting that electrons orbit the nucleus at specific distances. The theoretical calculations of Bohr agreed with experimental observations. |
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What contribution did Niels-Bohr make in furthering our understanding of the structure of the atom. |
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Later experiments led to the idea that the positive charge of any nucleus could be subdivided into a whole number of smaller particles, each particle having the same amount of positive charge. The name proton was given to these particles. |
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Which subatomic particle gives the nucleus of the atom a positive charge? |
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The experimental work of James Chadwick provided the evidence to show the existence of neutrons within the nucleus. This was about 20 years after the nucleus became an accepted scientific idea. |
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What discovery did James Chadwick make that advanced our understanding of the structure of an atom? |
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Students should be able to describe why the new evidence from the scattering experiment led to a change in the atomic model |
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How did the evidence of alpha particles scattering lead to a change in the atomic model? |
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Students should be able to describe the difference between the plum pudding model of the atom and the nuclear model of the atom. |
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Describe the currently accepted structure of the atom |
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Details of experimental work supporting the Bohr model are not required. |
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Details of Chadwick's experimental work are not required. |
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