Niels Bohr was the first scientist to apply the quantum theory of Max Planck to the structure of the atom. For this he won the Nobel Prize in 1922. His theories and contributions to physics would leave a lasting effect on the world of science today. With the new perception of the atom, further studies were accurately conducted on the properties of atoms, molecules and matter in general.Bohr stated that the electrons orbiting the nucleus of an atom existed only in discrete energy states, or levels. The electrons would fill the lowest level of energy possible as well. However, Bohr had made a mistake in his theory of the structure of the atom. He described it, as, in effect, a small solar system in which the nucleus was the sun and the electrons were the planets. Thus, he said, electrons orbited the nucleus in predetermined, cyclical paths. This statement does not comply with the uncertainty principle, though, because one can never know the exact location and velocity of any particle. Bohr's electron model worked accurately for hydrogen only.What Bohr's energy level theory explained, and accurately it should be noted, was the spectral lines produced by an element under intense heat. When different elements are heated, they jump energy levels and then jump back down releasing quantized amounts of energy. This corresponded with the line spectrum seen when a gas such a hydrogen is heated. This line spectrum provided evidence that Bohr's theory of actual electron energy levels was true.Bohr did not provide a clear understanding of how electrons moved, but provided the great clue of how their energy was quantized. This would lead to many discoveries about the orbitals and shapes of atoms.