Chapter 4 Spectroscopy Parts 1 & 2
Quantum Leaps A quantum leap is a change of an electron from one energy state to another within an atom. Quantum leaps cause the absorption and emission of electromagnetic radiation in which “excited” atoms release small packets of electromagnetic energy called photons.
Some Uses and Examples of “Exciting” Atoms (Quantum Leaps)
Northern lights (Aurora’s) are one of nature's most beautiful manifestations of the ability of electrons to jump between quantum states
Northern Lights Video (3:57)
Aurora Borealis
Did you ever wonder how we know what the universe is made of?
The entire article is posted near the door of the classroom if you would like to read more.
Star Finder Video - Fingerprints of Light (10:05) Full Video (13:50)
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
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.
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”. Chapter 4 Worksheet 3. Study Guide Chapter 4.