Problem

Rutherford's planetary model pictures electrons orbiting a dense nucleus like planets around the sun, held in place by electrical attraction rather than gravity. The key insight from his scattering experiment was that atoms are mostly empty space with a tiny, positively charged core—a radical departure from the "plum pudding" idea of diffuse positive charge. However, classical physics predicted that orbiting electrons should constantly radiate energy and spiral into the nucleus in a fraction of a second, which clearly doesn't happen. Bohr resolved this crisis by proposing that electrons occupy only certain discrete energy levels or "shells," where they can orbit stably without radiating, and jump between levels by absorbing or emitting specific packets of light—introducing quantization to atomic structure and explaining why atoms are stable and produce characteristic spectral lines.

Rutherford's planetary model pictures electrons orbiting a dense nucleus like planets around the sun, held in place by electrical attraction rather than gravity. The key insight from his scattering experiment was that atoms are mostly empty space with a tiny, positively charged core—a radical departure from the "plum pudding" idea of diffuse positive charge. However, classical physics predicted that orbiting electrons should constantly radiate energy and spiral into the nucleus in a fraction of a second, which clearly doesn't happen. Bohr resolved this crisis by proposing that electrons occupy only certain discrete energy levels or "shells," where they can orbit stably without radiating, and jump between levels by absorbing or emitting specific packets of light—introducing quantization to atomic structure and explaining why atoms are stable and produce characteristic spectral lines.