9th Grade IPC Chapter 18.5 Sources of Light
fluorescent bulbs contain what type of gas
mercury
emit light when electrons move through a gas or a mixture of gases inside glass tubing
neon light
incandescent bulbs are filled with a mixture of what two gases at low pressure
nitrogen and argon
_______ lights are energy efficient and give off very bright light
sodium vapor
contain a small amount of solid sodium, as well as a mixture of neon and argon gas
sodium-vapor light
what is the filament of an incandescent bulb made of
tungsten
these type of bulbs last longer than incandescent bulbs
tungsten-halogen bulbs
have a small amount of halogen gas in them
tungsten-halogen light
how does a fluorescent bulb work
electrodes in the fluorescent bulb emit electrons that cause the mercury atoms to emit ultraviolent rays. These rays cause the phosphor to emit light
when _____ flows through the filament of an incandescent bulb, the filament gets hot and emits light
electrons
how does an incandescent light bulb work
electrons flow through the filament, the filament get hot and emits light
in the process of _________, a material absorbs light at one wavelength and then emits light at a longer wavelength
fluorescence
the mixture warms and the heat causes the sodium to change from a solid to a _____
gas
incandescent bulbs give off most of their energy as
heat, not light
light produced when an object get hot enough to glow is
incandescent
What are the six common light sources
incandescent fluorescent laser neon tungsten-halogen sodium-vapor bulbs
as electric current passes through a sodium-vapor bulb, it _____ the gas mixture
ionizes
a device that generates a beam of coherent light
laser
the word laser stands for
light amplification by stimulated emission of radiation
objects that give off their own light
luminous
a solid material that can emit light by fluorescence
phosphor
fluorescent light bulbs emit light by causing a phosphor to steadily emit
photons
laser light is emitted when excited atoms of a solid, liquid or gas emit
photons
the bulb for a tungsten-halogen bulb is made of _____ because it has a high melting point, otherwise the bulb would start to melt when it get hot
quartz
what gases the neon light to appear in different colors
the type of gas in the tubing and the color of glass used to contain the gas
Why are fluorescent light bulbs used in office buildings and schools
they do not get as hot as incandescent bulbs because they emit most of their energy as light, which means they are very efficient
how are tungsten-halogen bulbs different from incandescent bulbs
they have a small amount of halogen gas in them
inside a tungsten-halogen bulb, electrons flow through a _____ filament, the filament gets hot and emits light
tungsten
light in which waves have the same wavelength, and the crests and troughs are lined up is
coherent light
lasers can be used to
cut metal and make computer chips, to cut or repair damaged tissue, carry information, and measure distance