Atomic Emission and Electron Energy Levels
Flame Tests Atomic Emission and Electron Energy Levels AES, or atomic emission spectroscopy, is a method which chemically analyzes the particular wavelength of a sample element to identify and determine the abundance of this certain element. The wavelength of the atomic spectral line unveils the identity of the element while the emitted light intensity is proportional to the number of atoms in the element. The flame test is also a very effective way to identify an individual element. The color of the flame can be described in terms of its wavelength and can be used to identify the element. Energy can be added to atoms in a variety of ways.
When heat energy is added, the excited electrons in the atoms emit light while falling back to lower electron energy levels. The light given off has wavelengths and colors that are unique to the element and depend on the amount of energy originally absorbed. Usually, each excited atom will only emit one type, or color, of light. There is a normal tendency for the electrons to make a transition or drop back down to the ground state from these excited energy levels. The energy levels in atoms and ions are crucial to the production and the detection of light. These electrons move throughout the energy levels in atoms and molecules.
Atomic Emission and Electron Energy Levels Essay Example
The colors of the emitted light from these particles are dependent on these electron jumps between the shells. When an electron makes a transition from a higher energy level to a lower one, a photon, or particle of light, is produced and emitted. This process can happen in a single step emitting one photon in the process, or the electron can make this trip back down to the ground state in a series of several smaller steps. A photon is emitted with each step. Different elements emit different emission spectra when they are excited because each element has a unique energy level system or energy shell.
The difference in the set of emission colors is due to the fact that all elements have different and unique energy level spacing. In any situation, the energy of each photon emission is equal to the difference in the energy between the excited state and the state at which the electron stops moving and relaxes. This is why the color of the emitted light is determined by the amount of energy emitted by the photon. Observing the colors when heat energy is added to a substance is a valuable method of identification of the element. Visible light is a form of electromagnetic radiation and makes up the electromagnetic spectrum.
This spectrum is measured by the wavelengths of the radiation. Most forms of electromagnetic radiation are invisible; however, there is a visible portion of the spectrum that is actually detectable by the human eye. The visible spectrum spans from about four hundred nanometers in wavelength to about seven hundred nanometers. The light emitted at the beginning of the visible spectrum is more violet or blue in color. The light emitted at the end of the visible spectrum is more orange or red in color. However, an infinite number of shades of each color may be observed.
When heat energy is added during the flame test, the colors of the flame of the metal ions are as followed: Calcium – Orange Copper – Blue/Green Lithium – Crimson/Red Sodium – Yellow Potassium – Pale Violet Strontium – Scarlet/ Red Therefore, strontium would have the longest wavelengths on the visible spectrum out of the given elements for this lab. Its flame is bright red in color. Lithium would have the second longest wavelengths out of the given elements. Its flame is a lighter reddish color. Calcium would have the third longest wavelengths out of the given elements. Its flame is an orange color.
Sodium would have the fourth longest wavelengths out of the given elements. Its flame is yellow in color. Copper would have the fifth longest wavelengths out of the given elements. Its flame is a bluish/pale green color. Finally, potassium would have the sixth longest, or the shortest wavelengths out of the given elements. Its flame burns light purple or violet in color. With this being said, it is easy for elements to be identified with the help of the flame test. This is why the flame test is so valuable to scientists who have to deal with energy and elements like these on an everyday basis.