Quantum The amount of energy needed to move an electron from it’s present energy level to the next higher one

Ground State The lowest energy level occupied by an electron when an atom is in its most stable energy state

Electromagnetic Radiation A series of energy waves that travel in a vacuum at 3.0 X 1010 cm/s; includes radio waves, microwaves, visible light, infrared and ultraviolet light, x-rays, and gamma rays

Frequency The number of wave cycles that pass a given point per unit of time; there is an inverse relationship between a frequency and the wavelength of a wave

The SI unit of frequency equal to one cycle per second Hertz The SI unit of frequency equal to one cycle per second

Spectrum Range of wavelengths of electromagnetic radiation; wavelengths of visible are separated when a beam of white light passes through a prism

Atomic Emission Spectrum A pattern of frequencies obtained by passing light emitted by atoms of an element in the gaseous state through a prism; the emissions spectrum of each element is unique to that element

Planck's Constant A number used to calculate the radiant energy absorbed or emitted by a body based on the frequency of radiation

Photons A quantum of light; a discreet bundle of electromagnetic energy that behaves as a particle

Laboratory 3 Atomic Emissions For this demonstration, you will observe a tube of hydrogen gas connected to a high-voltage power suppiy. This light can be viewed through a spectroscope or a diffraction grating lens. When the slit at the end of the spectroscope is aimed toward the light, the colors of the spectrum appear separately off to the sides of the slit

Laboratory 3 Atomic Emissions a) What colors do you see in the spectrum of light given off by hydrogen gas? b) Make a drawing in your Notebook of what you see inside the spectroscope. Make sure to label each band with the colors and spacing between them that you observe.

Laboratory 3 Atomic Emissions Now we’ll repeat this process for two other elements, helium and argon.

Laboratory 3 Atomic Emissions

Laboratory 3 Atomic Emissions Metals can be identified by characteristic colors, when a compound containing the metal is heated in a burner flame. The purpose of this demonstration is to show the colors and to associate them with the metal in the compound. Note: All the anions are the same (chloride) and do not give a color.

Laboratory 3 Atomic Emissions Materials BaCl2, CaCl2, CuCl2, SrCl2, NaCl, KCl Bunsen Burner Procedure Soak wooden sticks in 1 M solutions of each salt overnight. Hold stick over Bunsen burner flame and observe color.

Laboratory 3 Atomic Emissions Observations Metal Cation Color Fe2+ Ca2+ Cu2+ Sr2+ Na1+ K1+