WHAT IS FASTER THAN THE SPEED OF LIGHT? NOTHING!!!!

Electromagnetic Radiation Any wave of energy traveling at a speed of ___________ is called electromagnetic radiation. It is a form of energy produced by ___________________________________ There are many types of electromagnetic radiation and each type has a different _______________ and _______________. Here are the types of electromagnetic radiation from longest to shortest wave or lowest to highest frequency. These are also in order from lowest to highest energy. light Oscillating electric or magnetic waves frequency wavelength

Electromagnetic Radiation Unlike other kinds of energy, electromagnetic radiation can travel through _____________________ SPACE!!!!

Electromagnetic Radiation (1) Radio Waves -- used in __________________ (2) Microwaves-- broadcasts TV signals and used to _____ _______. (3) Infrared (IR) -- we feel this as _____; _________ & ______ can “see” this. communications cook food heat Snakes owls infrared image of a cat infrared image of heating pipes under a floor

Infrared Vision

Electromagnetic Radiation (4) Visible Light -- the only radiation we can detect with our eyes. It can be separated into the colors of the spectrum with a __________. ROYGBIV (5) Ultraviolet (UV) -- gives you a _____________; _________ can “see” this; some of this radiation from the sun gets blocked by the ___________ layer prism sunburn Bees ozone flower photo under normal light flower photo under UV light

Electromagnetic Radiation (6) X-rays -- used in medicine Ouch!

Electromagnetic Radiation (7) Gamma Rays-- some radioactive substances give it off. Gamma rays kill living cells. Interesting superhero facts: Superman has x-ray vision. The Incredible Hulk was “created” by an accidental overdose of gamma radiation. The Fantastic Four were “created” by cosmic rays.

How Light is Produced When atoms get hit with energy (by _____________ them with electricity or by ____________ them up), the electrons absorb this energy and __________ to a higher energy level. Figure (a) As they immediately fall back down to the “____________ state”, they give off this energy in the form of a particle of ___________ (or other types of electromagnetic radiation) called a _____________ (quanta of light. Figure (b) zapping heating jump ground light photon

How Light is Produced Each photon emitted has a specific ___________ (or frequency). The color of the light that is given off depends on how _____ the electron _______ (which depends on how big of a jump it originally made.) The farther the fall, the ___________ energy the photon has. color far fell greater

How Light is Produced energy Since electrons are located only in certain __________ levels (or orbitals) around the nucleus, only certain specific _________ of light are emitted. Scientists use a _________________ to separate these colors into bands of light. These bands of color look like a ______ code of color which is characteristic of that element. No two elements produce the same ______________ of colors. This can be used to distinguish one element from another contained in a sample. (See Fig. 13.11) color spectroscope bar spectrum

Emission Spectrum Hydrogen Spectrum Neon Spectrum

Get Ready for Your Flame Test Lab Photographs of flame tests of burning wooden splints soaked in different salts. This technique is called emission spectroscopy. methane gas wooden splint sodium ion calcium ion copper ion strontium ion 13

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Flame Tests for Certain Metals BORAX BEAD TESTS FOR CERTAIN METALS (All beads formed in the oxidizing flame) 15

Fireworks 16

Fireworks The chemistry of fireworks – Colors of fireworks due to atomic emission spectra – A typical shell used in a fireworks display contains gunpowder to propel the shell into the air and a fuse to initiate a variety of redox reactions that produce heat and small explosions – Thermal energy excites the atoms to higher energy states, and as they decay to lower energy states, the atoms emit light that gives the familiar colors Copyright © 2007 Pearson Benjamin Cummings. All rights reserved. 17

Copyright © 2007 Pearson Benjamin Cummings. All rights reserved. 18

Common chemicals used in the manufacture of fireworks Oxidizers Fuels (Reductants) Special Effects Ammonium perchlorate aluminum Blue flame: copper carbonate, copper sulfate, or copper oxide Barium chlorate antimony sulfide Red flame: strontium nitrate or strontium carbonate Barium nitrate charcoal White flame: magnesium or aluminum Potassium chlorate magnesium Yellow flame: sodium oxalate or cryolite (Na3AlF6) Potassium nitrate sulfur Green flame: barium nitrate or barium chlorate Potassium perchlorate titanium White smoke: potassium nitrate plus sulfur Strontium nitrate Colored smoke: potassium chlorate and sulfur, plus organic dye Whistling noise: potassium benzoate or sodium salicylate White sparks: aluminum, magnesium, or titanium Gold sparks: iron filings or charcoal Almost any combination of an oxidizer and a fuel may be used along with the compounds needed to produce a desired special effect. Copyright © 2007 Pearson Benjamin Cummings. All rights reserved. 19