Subject: General ChemistryLecturer: Dr. Ajith H. Herath|
Name: Kavini de Silva|
Niels Bohr applies quantum theory Rutherford’s Atomic Structure by assuming that electrons travel in stationary orbits defined by their angular momentum. This led to the calculation of possible energy levels for these orbits and the postulation that the emission of light occurs when an electron moves into a lower energy orbit.
The Atomic Spectrum is a series of lines of color produced when light from an excited atom is passed through a prism. It is also known as a line spectrum.
Each element has its own unique atomic spectrum. Because of their unique nature, atomic spectra are also referred to as the "fingerprints of the elements." The series of lines of color that an atom will produce is related to the locations of the electrons on that atom and their relationship with the nucleus. Atomic spectra were fundamental pieces of experimental information used by chemists in the development of the electronic structures of atoms. By studying the colors emitted by the different elements, it is possible to work backwards to the sources of those colors. In this way it is possible to determine the electronic structures of the elements. Most of the basic information known today about electronic structures was derived from studying the light emitted by the atoms. |
The process of exciting an atom, involves adding energy to the atom. This can be done in a variety of ways. Simply heating a sample of an element up in an open flame will excite electrons. Passing electricity through a sample of an element will excite electrons. The colored lights observed when sky rockets explode are a result of burning gunpowder exciting electrons within atoms of elements packed with the gun powder.|
A continuous spectrum will be a spectrum that contains all colors of light. It is commonly referred to as a "rainbow" when applied to the visible region of light. A single element does not produce a continuous spectrum. A continuous spectrum, or rainbow, when observed in nature, is usually the result of the spectra of many elements superimposed on top of each other. In addition, the spectrum produced by sun light in a continuous spectrum.
A Discontinuous Spectrum will appear as a "rainbow" with certain colors missing. This type of spectrum is produced by each element individually. The locations of the colors that are present and the gaps in color serve as clues to the arrangements of electrons on the atoms. This is also referred to as a "line spectrum", or if coming from a single element, an "atomic spectrum."| Electromagnetic radiation
Electromagnetic Radiation, or EMR, is basically another name for light. It is energy that is released by a charged object as it vibrates in a magnetic field. As electrons vibrate up and down on an atom, they will produce EMR. EMR is described by three variables--energy, wavelength and frequency. By studying the EMR produced by atoms it becomes possible to indirectly study the electronic structures of atoms.| |
Electromagnetic radiation spectrum
The Electromagnetic Radiation Spectrum, or EMR Spectrum, is a full "rainbow" of all colors of light, both visible and non-visible. To a large degree it is a theoretical spectrum, in that no real system is capable of producing all colors of EMR. The EMR Spectrum is generally broken down into three...