Download Light Bulbs

Mr. Fleming
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D. 5 Explain how electricity is used to
produce heat and light in incandescent bulbs
and heating elements.
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Light= Excitation of Electrons
Ground State
Excited State
Ground State

Light= Excitation of Electrons
◦ Light Bulbs in Microwave
◦ Atoms in Tungsten filament are excited by
electricity
 Abnormally high melting point
◦ Measure of power in light bulb is Watt
◦ Most energy given off as heat
 Only 10% goes to light
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Contains argon and mercury instead of
tungsten.
Electricity excites gas molecules in light bulb
Most energy is converted into visible light
instead of heat.
Mercury is highly toxic chemical
•
Ideal for replacement of
incandescent lamps
• Saves up to 75% on energy use
• Lasts 7-10 times longer than an
incandescent
• Low thermal energy output
▪ Can use up to 50% less
energy than a CFL.
▪ Widespread use over the
next 20 years could
reduce lighting energy
demand by 33%.
▪ Currently more expensive
to purchase compared to
incandescent and CFLs.
The NEED Project
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How LED works
Present in many electronics
Do not have filament
Most energy efficient
The NEED Project
The NEED Project

What is excited to produce light in a CFL?
Argon & Mercury Vapor

What is excited to produced light in an
incandescent light bulb?
Tungsten Filament

What is the most energy efficient light bulb?
LEDs

Name one disadvantage with using this light
bulb?