What was Niels Bohr’s most important discovery? Niels Bohr proposed a model of the atom in which the electron was able to occupy only certain orbits around the nucleus. This atomic model was the first to use quantum theory, in that the electrons were limited to specific orbits around the nucleus.

In 1913, Niels Bohr proposed a theory for the hydrogen atom, based on quantum theory that some physical quantities only take discrete values. Electrons move around a nucleus, but only in prescribed orbits, and If electrons jump to a lower-energy orbit, the difference is sent out as radiation.

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Niels Bohr/Professions

Bohr Atomic Model : In 1913 Bohr proposed his quantized shell model of the atom to explain how electrons can have stable orbits around the nucleus. To remedy the stability problem, Bohr modified the Rutherford model by requiring that the electrons move in orbits of fixed size and energy.

Working in the laboratory of his father (a renowned physiologist), Bohr conducted several experiments and even made his own glass test tubes.

The Nobel Prize in Physics 1922 was awarded to Niels Henrik David Bohr “for his services in the investigation of the structure of atoms and of the radiation emanating from them.”

This atomic model is known as the quantum mechanical model of the atom. In 1932, James Chadwick bombarded beryllium atoms with alpha particles. An unknown radiation was produced. Chadwick interpreted this radiation as being composed of particles with a neutral electrical charge and the approximate mass of a proton.

In 1932, the physicist James Chadwick conducted an experiment in which he bombarded Beryllium with alpha particles from the natural radioactive decay of Polonium. The resulting radiation showed high penetration through a lead shield, which could not be explained via the particles known at that time.

Margrethe Norlungm. 1912–1962
Niels Bohr/Spouse

Niels Bohr/Wife

The Nobel Prize in Physics 1935 was awarded to James Chadwick “for the discovery of the neutron.”

In 1932, Chadwick made a fundamental discovery in the domain of nuclear science: he proved the existence of neutrons – elementary particles devoid of any electrical charge. For this epoch-making discovery he was awarded the Hughes Medal of the Royal Society in 1932, and subsequently the Nobel Prize for Physics in 1935.

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