According to Thomson's atomic model, how was the positively charged part of the atom described?

• A. As a uniform sphere of positive charge in which electrons are embedded
• B. As discrete positive particles orbiting around the electrons
• C. As a cloud of positive charge surrounding the electrons
• D. As a dense central nucleus containing all the positive charge

Answer: (A)

Verified step by step guidance

1. Recall that Thomson's atomic model is often called the "plum pudding model." It was proposed before the discovery of the atomic nucleus.
2. Understand that in Thomson's model, the atom is envisioned as a positively charged sphere that provides the overall positive charge of the atom.
3. Recognize that the negatively charged electrons are embedded within this positive sphere, much like plums in a pudding, to balance the charge and make the atom neutral.
4. Note that this model does not include a dense central nucleus or discrete positive particles orbiting electrons; those ideas came later with Rutherford's and Bohr's models.
5. Therefore, the positively charged part of the atom in Thomson's model is described as a uniform sphere of positive charge in which electrons are embedded.