Presentation on theme: "Sun- nuclear fusion Process: H + H He + Energy All elements are made like this… we are all star dust! Qualities and Applications: All colours."— Presentation transcript:
Sun- nuclear fusion Process: H + H He + Energy All elements are made like this… we are all star dust! Qualities and Applications: All colours and types of light emitted This light energy fuels life on earth
Incandescence - light emitted from a very hot object Process: Electrons passed through a wire (electricity) generates heat. Qualities and Applications: Very Bright Very inefficient only 5% of energy converted to light 95% to heat
Electric Discharge- light emitted from a heated gas, instead of a heated wire. Process: Electrons flowing through a gas, heat it up, and light is emitted Common form is the sodium vapour bulb where electricity is passed through a tube with a drop of sodium and mercury.
Fluorescence- substances that convert UV light into visible light Process: Form of electric discharge, light emitted from mercury in a tube. Mercury produces ultra violet light which hits phosphor coating on glass which emits visible light. Qualities and Applications: 80% efficient 20% lost as heat Last 10x longer than incandescent bulbs Fluorescence dyes in money, semen, blood
Luminescence- light produced without heating an object Process: The energy used to excite the atoms can come from a variety of sources. For example, Fluorescence is a type of luminescence because the energy used to excite the phosphor in a fluorescent bulb comes from ultraviolet light. Phosphorescence, chemiluminescence, and bioluminescence are types of luminescence.
Phosphorescence - light emitted from phosphorescent materials Process: Materials store energy and release it slowly over time Qualities and Applications: Glow in the dark objects Dim lights
Chemiluminescence- light produced from the energy released in a chemical reaction Qualities and Applications: Glow sticks Dim/long lasting lights
Bioluminescence- light produced by chemiluminescence inside a living organism Qualities and Applications: Fire flies Some fish Jelly fish Bacteria Algae Most produced by bacteria inside other living things