Chapter 4 Spectroscopy Part 2

Spectroscopy is the study of the energy which is given off and absorbed when atoms go from the ground state to the excited state and back again. Spectroscopy is often used in chemistry for the identification of substances, through the spectrum absorbed or emitted.

Spectroscope

Hiding This Slide at this time. Can add it if we find we have time.

Fireworks

Neon Signs

Light Sources – Mercury CFL’s The average rated life of a CFL is between 8 and 15 times that of incandescents. CFLs typically have a rated lifespan of between 6,000 and 15,000 hours, whereas incandescent lamps are usually manufactured to have a lifespan of 750 hours or 1,000 hours. Mercury Vapor Lamp

Spectrum of a CFL bulb. The camera had a diffraction grating in front of the lens. The discrete images are produced by the different colors in the light, a line spectrum. An incandescent lamp would instead have a continuous band of color.

American and 2 Japanese Physicists Share 2014 Nobel Prize for Work on LED Lights

LEDs LEDs, (Light emitting diodes), are found in all kinds of devices. They form numbers on digital clocks, transmit information from remote controls, light up watches. Collected together, they form the illuminated screens on cell phones and television screens. Basically, LEDs are just tiny light bulbs that fit easily into an electrical circuit. But unlike ordinary incandescent bulbs, they don't have a filament that will burn out, and they don't get especially hot.

LEDs LED’s are illuminated solely by the movement of electrons. The lifespan of an LED is impressive lasting 10 times as long as a fluorescent bulb and 100 times as long as an incandescent bulb. LED bulbs do not have toxic mercury as do CFL’s. Due to low power requirements, it can be powered by cheap local solar power. Thus bringing the advantage of electrical devices to places that lack electrical power grids. Currently upfront costs are higher than many consumers which to pay but costs are continuing to drop as technology improves.

In the future, some of the most incredible uses of LEDs will actually come from organic light emitting diodes, or OLEDs which are flexible, allowing scientists to create bendable lights and displays. (Imagine rolling your TV up like a poster and carrying it with you anywhere).

Lasers You'll find them in everything from CD players to dental drills to high-speed metal cutting machines to measuring systems. Tattoo removal, hair replacement, eye surgery -- they all use lasers.

What else can lasers be used for? Sharks

I want sharks with laser beams attached to their heads.

Flame Tests

Flame Tests A flame test is a procedure used in chemistry to detect the presence of certain metal ions based on each element's characteristic emission spectrum.

..\..\..\..\Videos\Flame Tests.wmv Video: Flame Tests (27seconds) ..\..\..\..\Videos\Flame Tests.wmv

Video: Molecular Fingerprints (15 min.) Worksheet is in notebook. ..\..\..\..\Videos\World of Chemistry\Molecular Fingerprints.mpg

Homework Due Tomorrow Lab Summary: “Flame Tests”. Study Guide Chapter 4. Chapter 4 Worksheet 3.