The size of the nucleus is very large compared to the size of the atom.
Explanation
The structure of an atom was elucidated significantly by Ernest Rutherford’s Alpha Particle Scattering Experiment. This experiment led to the Nuclear Model of the Atom, which established the properties of the nucleus relative to the rest of the atom.
Statement-wise Analysis:
- Statement The nucleus is positively charged. is Correct: The nucleus is located at the center of the atom and contains protons and neutrons. Since protons are positively charged and neutrons are neutral, the overall charge of the nucleus is positive.
- Statement Electrons revolve around the nucleus in circular paths. is Correct: According to the planetary model (Rutherford) and subsequently the Bohr model, negatively charged electrons revolve around the positively charged nucleus in specific paths or orbits. While modern quantum mechanics describes these as probability clouds (orbitals), in the context of fundamental atomic models, the description of electrons revolving around the nucleus is accepted as a basic structural characteristic.
- Statement The size of the nucleus is very large compared to the size of the atom. is Incorrect: The size of the nucleus is extremely small compared to the total size of the atom. The radius of an atom is approximately 10–10 m, whereas the radius of the nucleus is about 10–15 m. The nucleus is roughly 100,000 times smaller than the atom. If an atom were the size of a cricket stadium, the nucleus would be comparable to a cricket ball placed at the center.
- Statement Most of the space inside the atom is empty. is Correct: In Rutherford’s experiment, the vast majority of alpha particles passed through the gold foil undeflected. This observation proved that most of the space inside an atom is empty.
Key Takeaway:
The atomic nucleus is a dense, positively charged region that occupies a negligible volume compared to the total volume of the atom, leaving the majority of the atom as empty space.