Thomson's Model of Atom
Describes the 'plum pudding' model where electrons are embedded in a sphere of positive charge, and its initial acceptance and subsequent failure.
What is Thomson's Model of Atom?
A stable subatomic particle with a negative elementary electric charge.
Key points
- Understand the historical context of atomic models.
- Describe the key features of Thomson's plum pudding model.
- Explain the reasoning behind Thomson's model.
- Recognize the limitations of Thomson's model.
Common exam trap
Confusing Thomson's model with Rutherford's or Bohr's model.
Definitions
- Term
Electron
- Meaning
A stable subatomic particle with a negative elementary electric charge.
- Term
Plum Pudding Model
- Meaning
An early atomic model proposed by J.J. Thomson, where electrons are embedded in a uniform sphere of positive charge.
Learning objectives
Understand the historical context of atomic models.
Describe the key features of Thomson's plum pudding model.
Explain the reasoning behind Thomson's model.
Recognize the limitations of Thomson's model.
Prerequisites
Discovery of the electron
Concept of electrical charge (positive and negative)
Basic understanding of atomic neutrality
Common mistakes
Confusing Thomson's model with Rutherford's or Bohr's model.
Assuming the positive charge is concentrated rather than uniform.
Forgetting that this model was proposed *after* the discovery of the electron.
Keywords
Thomson
Plum Pudding Model
Electron
Atomic Structure
Positive Charge
Electrical Neutrality
1904
Practice preview
Which of the following statements accurately describes the Thomson model of the atom?…
easy
According to Thomson's model of the atom, the electrons are:…
easy
Which of the following statements about Thomson's model is INCORRECT?…
medium