How does the radius of a nucleus compare to that of an atom?

The radius of a nucleus is significantly smaller than that of an atom. In fact, the nucleus is roughly 1/10,000 the size of the entire atom. This vast difference in size is due to the structure of atoms, which consist of a central nucleus made up of protons and neutrons, surrounded by a cloud of electrons. While the nucleus contains nearly all of the atom's mass, it occupies a very small volume compared to the electron cloud.

This substantial disparity stems from the way atoms are structured. Atoms have a defined size largely influenced by the electron shells that surround the nucleus. In contrast, the nucleus itself is compact, with dimensions on the order of 1 femtometer (10^-15 meters), while an atom typically has a radius on the order of angstroms (10^-10 meters). Therefore, the correct answer reflects this relationship between the atomic and nuclear radii, illustrating just how much smaller the nucleus is compared to the whole atom.