Name the Scientist who proposed that electron are embedded in a positive sphere.

Correct option is A

Sol: The correct answer is (a) J.J. thomson

Key Points:

J.J. Thomson proposed the model of an atom where electrons are embedded in a positively charged sphere, often referred to as the "plum pudding model."

In 1904, Thomson proposed the plum pudding model of the atom. According to this model:

• The atom is composed of a uniform positive charge (the "pudding") in which electrons (the "plums") are embedded.
• The positive charge is spread throughout the atom, balancing the negative charges of the electrons, resulting in an overall neutral atom

​Thomson's plum pudding model was a crucial step in atomic theory, marking a transition from classical to modern physics and paving the way for further developments in our understanding of atomic structure.

Information booster:

Niels Bohr :

• Model: Bohr's atomic model, proposed in 1913, describes the atom as having a small, positively charged nucleus surrounded by electrons in discrete circular orbits.
• Key Features:
  • Electrons occupy specific energy levels or shells.
  • Electrons can only gain or lose energy by jumping between these defined orbits, explaining the quantization of energy.
  • The model successfully explained the spectral lines of hydrogen, correlating the energy transitions with emitted light.
• Limitations: While effective for hydrogen and hydrogen-like ions, it fails for multi-electron systems due to complex electron interactions
  

R. Rutherford:

• Model: Proposed in 1911, Rutherford's model introduced the idea of a dense nucleus at the center of the atom with electrons orbiting around it.
• Key Features:
  • The nucleus contains most of the atom's mass and is positively charged.
  • Electrons move in circular paths around the nucleus, similar to planets around the sun.
• Limitations: This model could not explain why electrons do not spiral into the nucleus due to electromagnetic radiation loss
  

D. Camillo Golgi:

• Contribution: Golgi is primarily known for his work in cell biology rather than atomic theory. He developed the Golgi apparatus concept, a cellular structure involved in processing and packaging proteins.
• Relevance: His work is significant in understanding cellular functions but does not pertain to atomic models.