Presentation on theme: "Luminous object: something that produces its own light The Moon is bright only because it reflects the Suns light. Therefore, the Moon is NOT luminous."— Presentation transcript:
luminous object: something that produces its own light The Moon is bright only because it reflects the Suns light. Therefore, the Moon is NOT luminous.
1. Incandescence: light that is emitted from a very hot object
sodium vapour lamps a) electric discharge neon lights 2. Luminescence: light that is generated without heating the object - types:
Bohr Model of the Hydrogen Atom
LEDs (light-emitting diodes)
b) chemiluminescence: light that is produced by a chemical reaction without a rise in temperature
c) bioluminescence: light that is produced by a biochemical reaction in a living organism
and mercury d) fluorescence: light that is emitted during exposure of the source to ultraviolet (UV) light compact fluorescent light (CFL) bulb tubular fluorescent light bulb
Efficiency of Fluorescent Vs. Incandescent Bulbs
Even though fluorescent bulbs are 4X as efficient as incandescent bulbs (20% vs. 5%), some people dont like them because: they find the light from fluorescent bulbs to be harsh. these lamps contain small amounts of mercury vapour, a toxic metal.
Because they contain mercury, used fluorescent lamps CANNOT be thrown in the garbage. In Oakville, Rona & The Home Depot will take back your used fluorescent bulbs.
Uses of Fluorescence forensic science black light theatre fluorescent fish money
e) phosphorescence: light that is emitted due to exposure of the source to UV light, and that continues to be emitted for some time in the absence of the UV light
Characteristics of Images Size bigger or smaller Attitude upright or inverted Location closer or farther Type real or virtual
Lens and mirror equation
Index of refraction n =c/v C-speed of light in a vacuum 3.0 x 10 8 m/s V-speed of light in medium