physics quiz 1 (3.1-3.8) Flashcards
define incandescence light
- light is produced as result of high temperature
- electrical energy passes from socket—>metal (filament) which turns into heat energy and is released as light
- not energy efficient
initial source of energy of incandescent light
electrical energy
define electrical discharge
- light is produced by passing electric current through gas
- electricity makes the gas glow
- as atoms gain and lose energy, light energy is released
initial source of electric discharge
electrical energy
define phosphorescence
- light produced by UV light absorption which emits over time (ex. glow in the dark items)
- non-luminous objects that become luminous near luminous sources
- light from luminous source is absorbed by phosphor atoms, light energy slowly converted into chemical energy, stored, converted into radiant energy
initial source of phosphorescence light
radiant (light energy)
define fluorescence
- immediately emits visible light after UV light absorption
- electrical energy from wall passes through mercury vapor, mercury vapour atoms absorb electrical energy, turns into UV radiation
- UV radiation strikes fluorescent coating on inside of lightbulb, light emitted
- contains mercury
initial source of fluorescent light
electrical energy
define chemiluminescence
- light is result of chemical reaction w/ little to no heat (ex. glow sticks)
- when some chemicals mix, chemical energy from molecules before the reaction convert into light
- no electrical current needed
initial source of chemiluminescence
chemical energy
define bioluminescence
- chemical reactions in living organisms producing light (with no heat)
- occurs when 2 chemicals made by an organism mix together (jellyfish, firefly)
- used by organisms that live in dark locations
initial source of bioluminescence
chemical energy
define triboluminescence
- light is product of scratching/crushing rubbing crystals to create friction and light
- created when chemical bonds in crystals are broken
-some crystals store a lot of chemical energy, when crystal is broken, chemical energy turns into light energy and released
initial source of triboluminescence
chemical energy
define light-emitting diode (LED)
- electrical current flows through semi conductors to produce light
- when electric current flows in allowed direction, light is emitted
- les heat, more energy efficient
initial source of light-emitting diode (LED)
electrical energy
define laser
LASER- light amplification by simulated emission of radiation
- lasers produce electromagnetic waves of the same energy level in the same direction
- pure in colour, concentrated, high intensity
- never look into a laser beam
initial source of laser light
electrical energy
define nuclear light (power plants)
- unstable nucleus (ex. uranium) breaks apart and nuclear energy turns into light (called nuclear fission)
initial source of nuclear light (power plants)
nuclear energy
define nuclear light (the sun)
-hydrogen atoms in sun fuse together to create helium (called nuclear FUSION)
- nuclear energy in hydrogen atoms are released as light (product of chemical reaction)
initial source of nuclear light (the sun)
nuclear energy
what is light
form of energy visible to humans which travels in form of waves
what is a wave
a disturbance that transfer energy from one point to another
