Presentation on theme: "What is light??. Light is a form of energy that is created from a different form of energy There are two types Incandescence- Light from heat or high."— Presentation transcript:
What is light??
Light is a form of energy that is created from a different form of energy There are two types Incandescence- Light from heat or high temperature Luminescence –Light from electron giving off energy https://www.youtube.com/watch?v=YnMP1Uj2nz0 What are the source of light you know of and which one do you think it fits into?
Luminescence Sources Chemiluminescence- Light given off by a chemical reaction Bioluminescence- Light given off by a chemical reaction within an organism
Luminescence Sources Electroluminescence- Luminescence cause by electric currents https://www.youtube.com/watch?v=BH9LI973H8w Cathodoluminescence- Electroluminescence cause by electron beams https://www.youtube.com/watch?v=qp6tNaUvfNI
Luminescence Sources Fluorescence- Luminescence where energy is given off by the movement of electrons to non-excited state. Electrons are found in atoms. They can get excited and take in energy. When they release that energy it comes off as light photons. Phosphorescence- is a delayed light that is created because electrons are stuck in a high energy state and has not given off the energy as light yet. https://www.youtube.com/watch?v=kLEHNYWQl68
What types of light bulbs do you have in your house? How often do the light bulbs need changing? What are some factors that you think about when buying light bulbs?
Which bulb would you choose? IncandescentL.E.DC.F.L. Lumens825800900 Wattage601114 Cost of bulb6.00 for 1211.984.98 for 2 Life Span1,00025,00010,000 Cost of running the light bulb over its life span $7.872$36.08$18.368
Which bulb would you choose? IncandescentL.E.DC.F.L Does it contain mercury no yes Can you recycle it? noyesno Is it dimmableyes no
Exit slip 1. Which light bulb are you likely to buy now that we have compared some? What factors are the most important to you in a light bulb? 2. Explain in your own words what is the difference between Luminescence and Incandescence light sources. 3. What is bioluminescence?