Electromagnetic Radiation (Light)

Electromagnetic Radiation Characteristics of Electromagnetic Radiation Produced by the motion of electrically charged particles moving back and forth.

Electromagnetic Radiation Characteristics of Electromagnetic Radiation The charged particles are surrounded by: Electric fields Magnetic fields

Electromagnetic Radiation Characteristics of Electromagnetic Radiation Transverse waves Do not require a medium

Electromagnetic Radiation Characteristics of Electromagnetic Radiation All electromagnetic waves Travel at 300,000,000 m/s in a vacuum Nothing travels faster than the speed of light!

Electromagnetic Radiation Characteristics of Electromagnetic Radiation Travels slower when passing through a medium

Electromagnetic Radiation Duel Nature of Electromagnetic Radiation Particle nature Travels in bundles of energy Bundles act like small particles Called photons

Electromagnetic Radiation Duel Nature of Electromagnetic Radiation

Electromagnetic Radiation Duel Nature of Electromagnetic Radiation Wave nature All electromagnetic waves travel at the same speed Frequency and wavelength are used to classify the waves in the electromagnetic spectrum

Electromagnetic Spectrum The electromagnetic spectrum is the complete range of electromagnetic waves placed in order of increasing frequency.

Electromagnetic Spectrum

Electromagnetic Spectrum

As the frequency increases: Wavelength decreases Electromagnetic Spectrum As the frequency increases: Wavelength decreases Photon penetrating energy increases

Radio Waves Uses: Communication (telephones, pagers, radio transmission, global positioning system Long wavelength and Low frequency Lowest Photon energy

Radio Waves

Microwaves Uses: Cooking, cellular phones, radar Long wavelength and Low frequency Lower Photon energy

Infrared Radiation Wavelength is only a little longer than visible light Uses – Remote controls, thermal energy transfer (radiant energy) including night vision, infrared photography, locating tumors (Remember all living objects give off infrared radiation.)

Infrared Radiation

Visible Radiation Only wavelengths that can be detected by the human eye Use – allow humans to see

Ultraviolet Radiation Higher frequency and shorter wavelength than visible radiation Uses– Produces vitamin D in human skin and can be used to kill bacteria and viruses (sterilize equipment) Warning! – too much can cause skin cancer; Ozone in the atmosphere blocks it

X-rays Higher frequency and photon energy – greater penetrating power Uses: X-ray pictures; rays will penetrate soft matter like skin and muscle, but it is absorbed by the harder bones

Gamma Rays Highest frequency -- greater penetrating power Uses: destroy human cells and can be used to kill cancerous cells

Review Get ready!

What produces electromagnetic radiation? Review What produces electromagnetic radiation?

What type of wave is electromagnetic radiation? Review What type of wave is electromagnetic radiation?

Name a wave that can travel faster than electromagnetic radiation? Review Name a wave that can travel faster than electromagnetic radiation?

Review What is a photon?

Name the longest electromagnetic wave. Review Name the longest electromagnetic wave.

Review What name do we give to all the electromagnetic waves arranged from longest wavelength to shortest wavelength?

Name electromagnetic wave used to see a child in a burning house. Review Name electromagnetic wave used to see a child in a burning house.

Concept Map