Which statement describes one feature of Rutherford's model of the atom?

• A. Most of the atom's mass and all of its positive charge are concentrated in a small nucleus.
• B. Atoms are indivisible and consist only of solid spheres.
• C. Protons and neutrons are evenly distributed throughout the atom.
• D. Electrons are arranged in fixed orbits at set distances from the nucleus.

Answer: (A)

Verified step by step guidance

1. Recall that Rutherford's atomic model was developed based on the gold foil experiment, which showed that alpha particles were mostly passing through the atom but some were deflected at large angles.
2. Understand that this experiment led Rutherford to propose that the atom has a small, dense, positively charged center called the nucleus, where most of the atom's mass is concentrated.
3. Recognize that Rutherford's model does not describe electrons as arranged in fixed orbits; that idea was introduced later by Bohr.
4. Note that Rutherford's model disproved the idea that atoms are indivisible solid spheres, which was part of Dalton's earlier atomic theory.
5. Conclude that the key feature of Rutherford's model is that most of the atom's mass and all of its positive charge are concentrated in a small nucleus, with electrons moving around this nucleus.