Atoms consist of a small, dense nucleus (discovered through the Geiger–Marsden–Rutherford experiment) containing protons and neutrons, surrounded by electrons in quantized energy levels.
Atomic transitions involve photon emission or absorption related to discrete energy differences, as shown by emission and absorption spectra.
The Bohr model introduced quantized electron orbits, but modern quantum mechanics describes electrons as probability clouds (orbitals).
Rutherford’s scattering provided evidence for a central nucleus, refuting the plum pudding model.
Spectral lines showed that electrons occupy discrete energy levels, supporting the Bohr model.
Experiments like head-on scattering and measurements of nuclear radii refined the understanding of nuclear structure and nuclear density.
The Bohr model correctly predicts energy levels for hydrogen atoms, useful in explaining spectral lines.
Rutherford’s nuclear model remains accurate regarding the existence of a dense central nucleus.
Older models still serve as approximations in contexts where full quantum mechanical descriptions are unnecessarily complex.
Geiger–Marsden–Rutherford experiment and the discovery of the nucleus
Nuclear notation where A is the nucleon number Z is the proton number and X is the chemical symbol
Emission and absorption spectra provide evidence for discrete atomic energy levels
Photons are emitted and absorbed during atomic transitions
The frequency of the photon released during an atomic translation depends on the difference in energy level as equations with Planck’s constant
Emission and absorption spectra provide information on the chemical composition
The relationship between the radius and the nucleon number for a nucleus equation and implications for nuclear densities
Distance of closest approach in head-on scattering experiments
Discrete energy levels in the Bohr model for hydrogen equation
The existence of quantized energy and orbits arise from the quantization of angular momentum in the Bohr model for hydrogen equation