University of Adelaide, Barr Smith Lawns — Photo Credit: By Pdfpdf (talk) - My camera, my software and I created this work entirely by ourselves., Public Domain, https://commons.wikimedia.org/w/index.php?curid=18049023
logo for University of Adelaide — Photo Credit: By Obtained from https://www.adelaide.edu.au and copyright owned by the University of Adelaide., Fair use, https://en.wikipedia.org/w/index.php?curid=56077618
Bohr and Margrethe Nørlund on their engagement in 1910 — Photo Credit: Niels Bohr Institute, Public Domain, https://commons.wikimedia.org/w/index.php?curid=24652845
Bohr model - hydrogen atom — The cake model of the hydrogen atom (Z = 1) or a hydrogen-like ion (Z > 1), where the negatively charged electron confined to an atomic shell encircles a small, positively charged atomic nucleus and where an electron jumps between orbits, is accompanied by an emitted or absorbed amount of electromagnetic energy (hν). The orbits in which the electron may travel are shown as grey circles; their radius increases as n2, where n is the principal quantum number. The 3 → 2 transition depicted here produces the first line of the Balmer series, and for hydrogen (Z = 1) it results in a photon of wavelength 656 nm (red light). Photo Credit: By JabberWok, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=2639910
Bohr model - hydrogen atom
The cake model of the hydrogen atom (Z = 1) or a hydrogen-like ion (Z > 1), where the negatively charged electron confined to an atomic shell encircles a small, positively charged atomic nucleus and where an electron jumps between orbits, is accompanied by an emitted or absorbed amount of electromagnetic energy (hν). The orbits in which the electron may travel are shown as grey circles; their radius increases as n2, where n is the principal quantum number. The 3 → 2 transition depicted here produces the first line of the Balmer series, and for hydrogen (Z = 1) it results in a photon of wavelength 656 nm (red light).
Werner Heisenberg (left) with Bohr at the Copenhagen Conference in 1934 — Photo Credit: By Fermilab, U.S. Department of Energy - Public Domain, https://commons.wikimedia.org/w/index.php?curid=6877522