Question 11

The Rutherford-Bohr model restricts the positive charge of the atom to the nucleus.

The Rutherford-Bohr model uniquely posits that the positive charge of an atom is concentrated in the nucleus, which is a significant advancement over the Thomson model. In contrast, Thomson's model depicted a uniform distribution of charge throughout the atom without a central nucleus.

A) The Rutherford-Bohr model identifies different elements by the numbers of particles present.

This statement is incorrect as both the Rutherford-Bohr and Thomson models do not primarily focus on identifying elements based on particle numbers. Instead, they describe atomic structure, and while the Rutherford-Bohr model does relate to atomic numbers, it is not a defining feature distinguishing it from the Thomson model.

B) The Rutherford-Bohr model maintains the observed neutral charge of atoms.

This statement is misleading because both models account for the neutrality of atoms. The Thomson model suggests a uniform charge distribution, while the Rutherford-Bohr model acknowledges the nucleus's positive charge balanced by orbiting electrons. Therefore, this is not a feature that differentiates the two models.

C) The Rutherford-Bohr model correctly describes the types of particles in the atom.

While the Rutherford-Bohr model accurately identifies protons and electrons as key components of an atom, so does the Thomson model, which also recognizes electrons. Thus, this statement does not highlight a unique feature of the Rutherford-Bohr model compared to the Thomson model.

D) The Rutherford-Bohr model restricts the positive charge of the atom to the nucleus.

This statement accurately reflects a fundamental distinction between the Rutherford-Bohr model and the Thomson model. The Rutherford-Bohr model specifically states that the positive charge resides in the nucleus, unlike the Thomson model, where charge is distributed throughout the atom.

Conclusion

The Rutherford-Bohr model's restriction of the positive charge to the nucleus is a key feature that sets it apart from the Thomson model's uniform charge distribution. This distinction highlights the evolution of atomic theory, where the understanding of atomic structure progressed from a diffuse arrangement to a more defined nucleus with orbiting electrons. All other options fail to capture this crucial difference, focusing instead on aspects that are not unique to the Rutherford-Bohr model.