Science - Light stuff Flashcards
Incandescence
Emission of light caused by heating the filament
- creates heat and is hot to touch
- uses a lot of electricity to make the metal glow for a light bulb
e.g. old lightbulbs, candles
Bioluminescence
A chemical reaction within a living organism
e.g. fireflies, deep sea fish (angular fish), jellyfish
Fluorescence
The ability of certain chemicals to give off visible light after absorbing radiation which is not normally visible
- Absorbs UV light then the object emits a visible light immediately
e.g. laundry detergent, highlighters, swirly lightbulbs
- Electric current flows through mercury vapour, emits UV light, which is absorbed by the phosphor, and re-emitted as visible light
Phosphorescence
energy (UV light usually) is absorbed by the object and emits visible light for an extended period
e.g. glow in the dark things (stickers)
Chemiluminescence
A direct by-product of a chemical reaction
- Little to no heat
e.g. Glowsticks
Triboluminescence
Light produced from friction (scratching, crushing, rubbing certain crystals)
e.g. crushing lifesaver candies
Electric discharge
Light is made when an electric current passes through a gas, causing it to glow
- gas is glowing
e.g. Neon signs, lightning
Electroluminescence
Light produced as a result of an electric current flowing through a semi-conductor (allows to flow in one direction)
e.g. LED lights, Christmas lights, traffic lights
Crest
The highest point of the electromagnetic spectrum
Trough
The lowest point of the electromagnetic spectrum
Rest position
No wave (just a straight line)
Wavelength
one complete wave (1 crest and 1 trough)
Amplitude
The wave height (from rest position to the top of crest or the bottom of trough)
Frequency
number of waves within a given time
Types of waves from lowest frequency to highest
and longest to shortest
Radio, microwave, infrared, visible (red light, or any coloured light), ultraviolet, x-ray, gamma ray
