AQA · GCSE · Physics
Course version: 8463 · Version from Sept 2016
Later experiments led to the idea that the positive charge of any nucleus…
Full specification wording
The development of the model of the atom (common content with chemistry): 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.
Once the nucleus was accepted, the next question was whether its positive charge was a single lump or made of parts.
Checked against the AQA 8463 specification (opens in a new tab) on .
- Point 9 of 12
- 4 key terms
Study notes
From the checked teaching notes for this specification point.
The idea
Once the nucleus was accepted, the next question was whether its positive charge was a single lump or made of parts. Experiments showed that the charge of every nucleus is a whole-number multiple of one fixed basic amount: never one and a half times it, never a fraction. That points to the nucleus being built from identical positively charged particles, with one element differing from the next by the number of them it contains. Hydrogen has one, helium two, lithium three, and so on up the periodic table. The idea came from experimental evidence, not from theory alone, which is why it took further work after the nuclear model was established.
What earns the marks
- Stating that the positive charge of a nucleus comes in whole-number multiples of a basic amount.
- Stating that each of these particles carries the same amount of positive charge.
- Stating that different elements have different numbers of these particles.
- Stating that experimental evidence, not theory alone, led to this idea.
Common mistakes and how to put them right
Suggesting a nucleus can carry a fractional amount of the basic charge.
Confusing these positive particles with electrons.
Crediting Chadwick with this discovery instead of with the neutron.
Saying the idea came directly from the alpha scattering experiment.
Exam tips
- Use the phrase whole number of particles, each with the same charge, which is the specification's own wording.
- Link the number of these particles to the atomic number of the element.
- Keep this step separate from the discovery of the neutron, which came about twenty years later.
Try the lesson
The start of the The development of the model of the atom (common content with chemistry): 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. lesson, made from checked teaching notes for this specification point.
Have a go first
Later experiments showed that the positive charge of a nucleus is made up of a whole number of smaller particles. What is the charge on each of these smaller particles?
Listen
Once the nucleus was accepted, the next question was whether its positive charge was a single lump or made of parts. Experiments showed that the charge of every nucleus is a whole-number multiple of one fixed basic amount: never one and a half times it, never a fraction. That points to the nucleus being built from identical positively charged particles, with one element differing from the next by the number of them it contains. Hydrogen has one, helium two, lithium three, and so on up the periodic table. The idea came from experimental evidence, not from theory alone, which is why it took further work after the nuclear model was established. A strong answer earns marks for these points. stating that the positive charge of a nucleus comes in whole-number multiples of a basic amount. stating that each of these particles carries the same amount of positive charge. stating that different elements have different numbers of these particles. stating that experimental evidence, not theory alone, led to this idea. Exam tip: Use the phrase whole number of particles, each with the same charge, which is the specification's own wording.
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Key words
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subdividing nuclear charge
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whole-number multiples
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identical particles
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experimental evidence
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See every definition
- subdividing nuclear charge
- The idea that the positive charge of any nucleus could be subdivided into a whole number of smaller particles.
- whole-number multiples
- The charge of every nucleus is a whole-number multiple of one fixed basic amount, never one and a half times it, never a fraction.
- identical particles
- The nucleus is built from identical positively charged particles, each particle having the same amount of positive charge.
- experimental evidence
- The idea came from experimental evidence, not from theory alone, which is why it took further work after the nuclear model was established.
Label the diagram
Some boxes have lost their names. Pick the right name for each number.
1Box 1
2Box 2
3Box 3
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