ᴛʀᴀɴsᴘᴀʀᴇɴᴛ ᴠs ᴏᴘᴀǫᴜᴇ ᴍᴀᴛᴇʀɪᴀʟs

 

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electrons generally bound to particular atom

oscillating electric fields of ems wave can cause outer

electrons to vibrate back and forth

natural frequency - creates resonance if matched

material with same resonant energy: light wave absorbed,

energy of light wave converted to thermal, interacts with

nearby atoms, raise temperature of material

opaque - absorb particular frequencies of light

ordinary window glass opaque to UV light, gets warm instead

material with different frequency: still set into vibration,

lower amplitude with shorter time

vibrating electrons generate ems waves, less heat energy

transparent - reemitted waves continuously absorbed and

emitted by neighboring atoms until wave exits from other side

time delay (nanoseconds) between when each atom absorb

and reemit wave

light passes more slowly through transparent materials than 

in a vacuum

if opaque, wave will not be passed through inside, reemitted

metals - opaque to most ems waves

outer electrons not bound to particular atoms

explains tendency to be good conductors of electricity and heat

electrons respond faster to electric fields, redistribute themselves,

set up identical electric field that cancels out wave

conductors - electrons can redistribute themselves

reflected light is outgoing wave

resistance to motion of electrons = less reflected light, more dull