Spectroscopy Is the science of studying the properties of light Visible light was in fact a mixture of different kinds of light Spectroscopy

Electromagnetic Waves Electromagnetic radiation that transfer energy as they travel through space. Travel at the speed of light (eight laps around Earth in one second) Nothing travels faster than the speed of light in a vacuum. “speed limit” for the universe. Electromagnetic Waves

Electromagnetic Spectrum Name for the range of electromagnetic waves when placed in order of increasing frequency

Wavelength Frequency The distance between successive crests (tops) of a wave How often a wave repeats in an amount of time Short wavelength High frequency Long wavelength Low frequency

Notice the wavelength is long (Radio waves) and gets shorter (Gamma Rays) CFU! In the Visible light section, Which color has a long wavelength?

GAMMA RAYS Shorter wavelength and higher frequency than X-rays Carry the greatest amount of energy and penetrate the most.

The Incredible Hulk was the victim of gamma radiation. (Don’t try this at home: you wont gain superpowers) Used in radiation treatment to kill cancer cells. x Can be very harmful if not used correctly.

Exploding nuclear weapons emit gamma rays. What do you think would happen if a nuclear weapon would explode over a major city? Exploding nuclear weapons emit gamma rays.

X- RAYS longer wavelength and lower frequency than Gamma rays Carry a great amount of energy Can penetrate most matter.

Bones and teeth absorb x-rays Bones and teeth absorb x-rays. (The light part of an x-ray image indicates a place where the x-ray was absorbed) X-rays from when a patient broke their collar bone and had a titanium rod installed.

Why do they put that lead vest on us? Too much exposure can cause cancer (lead vest at dentist protects organs from unnecessary exposure)

longer wavelength and lower frequency than X-rays ULTRAVIOLET (UV) RAYS longer wavelength and lower frequency than X-rays Carry more energy than visible light

Other Uses of UV Rays UV rays are used to activate chemicals. (teeth whitening & nail curing) UV rays are used to kill bacteria. (Sterilization of equipment)

Too much can cause skin cancer. Use sun block to protect against (UV rays) CFU! So far, which energy sources are cancer causing? UV rays also causes your skin to produce vitamin D (good for teeth and bones)

VISIBLE LIGHT WHICH COLOR HAS MORE ENERGY: RED OR BLUE? GREEN OR YELLOW? longer wavelength and lower frequency than UV rays. Electromagnetic waves we can see. Longest wavelength= red light Less energy Shortest wavelength= violet (purple) light More energy ROY G BIV

INFRARED RAYS Infrared= below red VISIBLE LIGHT LONGER wavelength and LOWER frequency than Visible light.

HEAT ENERGY!!! People and animals give off infrared rays. Objects such as heat lamps give off infrared waves. Thermogram—a picture that shows regions of different temperatures in the body. Temperatures are calculated by the amount of infrared radiation given off.

MICROWAVES Have the longer wavelengths and the lower frequency than infrared waves.

Used in microwave ovens. -Waves transfer energy to the water in the food causing them to vibrate which in turn transfers energy in the form of heat to the food. Also satellites

RADIO WAVES Have the longest wavelengths and lowest frequencies of all the electromagnetic waves. Lowest energy

RADAR (Radio Detection and Ranging) Global Positioning Systems (GPS) measure the time it takes a radio wave to travel from several satellites to the receiver, determining the distance to each satellite. RADAR (Radio Detection and Ranging) Used to find the speed of an object by sending out radio waves and measuring the time it takes them to return.

A radio picks up radio waves through an antenna and converts it to sound waves. Each radio station in an area broadcasts at a different frequency. # on radio dial tells frequency.