|The wavelengths of visible light emitted by an element as an excited electron falls back to ground state. Each element has its own individual bright-line spectrum.
|An atom with one more electrons not in the ground state or lowest energy level
|Atoms with the same atomic number but a different number of neutrons. For a given element, the number of protons in the nucleus remains constant, but the number of neutrons may vary. For example, 14C and 12C are isotopes of carbon.
|Principal Energy Levels
|In the Bohr Model of the atom, electrons are arranged around the nucleus of an atom in principal energy levels denoted by the by the numbers 1, 2, 3, 4, 5, 6, 7. Electrons in orbit near the nucleus are at lower energy levels than those in orbits farther from the nucleus.
|When electrons in an atom in the excited state return to lower energy levels, radiant energy of a specific frequency is emitted, producing the characteristic spectral lines which can be used to identify the element.
|An electron in the outermost principal energy level of an atom.