ch. 19 - light
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Ch. 19 - Light
I. Electromagnetic Radiation (p.528-535)
EM RadiationEM SpectrumTypes of EM Radiation
A. EM Radiation
Electromagnetic Radiationtransverse waves produced by the motion of electrically
charged particlesdoes not require a mediumspeed in a vacuum = 300,000 km/selectric and magnetic
components are perpendicular
A. EM Radiation
Photonstiny, particle-like
bundles of radiationabsorbed and released
by electronsenergy increases with wave
frequency
B. EM Spectrum
long
low f
low energy
short
high f
high energy
C. Types of EM Radiation
Radiowaveslowest energy EM radiation
C. Types of EM Radiation
RadiowavesFM - frequency modulation AM - amplitude modulation
Microwavespenetrate food and vibrate
water & fat molecules to produce thermal energy
C. Types of EM Radiation
Infrared Radiation (IR)slightly lower energy than
visible lightcan raise the thermal energy
of objectsthermogram - image made by
detecting IR radiation
C. Types of EM Radiation
Visible Lightsmall part of
the spectrum we can see
ROY G. BIV - colors in order of increasing energy
R O Y G. B I V
red orange yellow green blue indigo violet
C. Types of EM Radiation
Ultraviolet Radiation (UV)slightly higher energy than visible lightTypes:
• UVA - tanning, wrinkles• UVB - sunburn, cancer• UVC - most harmful,
sterilization
C. Types of EM Radiation
Ultraviolet Radiation (UV)Ozone layer depletion = UV exposure!
C. Types of EM Radiation
X rayshigher energy than UVcan penetrate soft tissue,
but not bones
C. Types of EM Radiation
Gamma rayshighest energy
EM radiationemitted by
radioactive atomsused to kill
cancerous cells Radiation treatment using radioactive cobalt-60.
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