Spectral Analysis of Atoms!! in chemistry, this is a method of analyzing the properties of matter( what atoms they are made of)… By looking at the colors of visible light that each type of atom gives off!

ELECTROMAGNETIC SPECTRUM If you see pure yellow – what wavelength are you seeing? @580nm What about seeing royal blue… wavelength?? @450 nm

The light we can see with the naked eye is only a very small portion of "light". Light is just energy that travels in the form of waves and particles and our eyes can pick up on certain wavelengths of it in the visible spectrum (approximately 400 – 750nm)

Robert Wilhelm Bunsen/ Gustav Robert Kirchhoff - 1859 These 2 brilliant men burned materials in flames, and noticed that certain elements burned certain colors in the flames. Ie. Sodium burns yellow, Barium green, Strontium red, etc… The spreading of the resulting light through prisms, allowed them to see a particular pattern of colors (bands of light) for each element = Line Spectra This is SPECTRAL ANALYSIS!!

Barium salts excited by heat in the flame emit color!! Color of the light is shone through a prism to separate it into it’s particular bands… And this is what we see… Looking at Barium’s Line Spectra – does it make sense why Barium burns GREEN??!!

This is the Line(emission) spectra for sodium… So… what color do you think it gives off when excited?

This is the Line(emission) spectra for Neon… So… what color do you think it gives off when excited?

The composition of a crushed rock sample was investigated using spectral analysis. The rock sample was dissolved in acid and heated to produce an emission spectrum as the unknown… Based on this spectral analysis it can be concluded that the rock sample contains… STRONTIUM only!

Every atom in the universe gives off energy in the form of visible light (Electromagnetic Radiation) when excited ( by heat/electricity)…so if we know what colors each type of atom give off- we can figure out what atoms are making up the matter we are looking at… For example…A STAR!!

Ever wondered how Astronomers know what kind of gases are present on other planets/Stars?? They look at all the colors of visible light being given off from the planet/star, and because they know what kind of bands of light each atom gives off, they can figure out what elements are present on the planet/star!

So all of this led scientists to conclude that there was a definite connection with the wavelengths an element emits, and the element's particular atomic structure! So what about the atoms structure causes energy to be released when it’s heated or electrocuted?

For now…Let’s take a look at this phenomena in the classroom! Answer…Next Day!! For now…Let’s take a look at this phenomena in the classroom!