Rutherford’s model introduced the nuclear model of an atom, in which he explained that a nucleus (positively charged) is surrounded by negatively charged electrons.

It came into existence with the modification of Rutherford’s model of an atom. The complete line spectra for the transitions represented in this animation are shown below (note, a hydrogen atom has additional lines related to transitions not shown here). What is Bohr’s Model of an Atom The Bohr model of the atom was proposed by Neil Bohr in 1915. In the Bohr model of the hydrogen atom we have one proton in the nucleus. Bohr’s model required only one assumption: The electron moves around the nucleus in circular orbits that can have only certain allowed radii. The animation provides data on the energy added and released and the resulting wavelengths of light emitted. In 1913, a Danish physicist, Niels Bohr (18851962 Nobel Prize in Physics, 1922), proposed a theoretical model for the hydrogen atom that explained its emission spectrum. Main Idea A visualization of the Bohr model and the hydrogen spectrum. 'Bohrs model of 1913 for the hydrogen atom had circular electron orbits about the proton like Earth orbits around the sun,' says Herschbach. This animation allows you to add different amounts of energy to see how the electron in a hydrogen atom responds, and then manually allow that electron to relax to specific orbitals within the atom (note that in nature electrons relax spontaneously and instantaneously). Bohrs model of the hydrogen atom was the first to incorporate quantum theory, and the key idea of his model was that electrons occupy discrete orbitals. Niels Henrik Bohr (1885-1962) was a Danish physicist who developed the atomic model and won the 1922 Nobel prize in physics. The popular theory of atomic structure at the time of Rutherford’s experiment was the plum pudding model. Rutherford explained the nucleus of an atom and Bohr modified that model into electrons and their energy levels. Figure1 The gold foil experiment was conducted under the supervision of Ernest Rutherford at the University of Manchester in 1909 by Hans Geiger and Ernest Marsden. Bohr’s theory explained that those spectral emission lines were due to the energy released by the relaxation of excited electrons between specific orbitals. Bohr theory modified the atomic structure model by explaining that electrons move in fixed orbitals (shells) and not anywhere in between and he also explained that each orbit (shell) has a fixed energy. Evidence that led to this proposal was the observation of line spectra – distinct bands of light emitted by atoms after they were excited by heat or electricity. In other words, Bohr’s work suggested that electrons do not move freely around the atom, but can only occupy specific energy levels within the atom. In 1913, Neils Bohr built on the work of Max Planck and Albert Einstein and proposed that the movement of electrons within an atom was quantized. Following the discoveries of hydrogen emission spectra and the photoelectric effect, the Danish physicist Niels Bohr (1885 1962) proposed a new model of the atom in 1913.

Bohr's atom model