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A General Electric NE-34 glow lamp, manufactured circa 1930. Neon was discovered in 1898 by William Ramsay and Morris Travers.The characteristic, brilliant red color that is emitted by gaseous neon when excited electrically was noted immediately; Travers later wrote, "the blaze of crimson light from the tube told its own story and was a sight to dwell upon and never forget."
In chemistry, polarity is a separation of electric charge leading to a molecule or its chemical groups having an electric dipole moment, with a negatively charged end and a positively charged end. Polar molecules must contain one or more polar bonds due to a difference in electronegativity between the bonded atoms.
A final class of white LED with mixed light is dim-to-warm. These are ordinary 2700K white LED bulbs with a small red LED that turns on when the bulb is dimmed. Doing so makes the color warmer, emulating an incandescent light bulb. [39]
Glow discharges are used as a source of light in devices such as neon lights, cold cathode fluorescent lamps and plasma-screen televisions. Analyzing the light produced with spectroscopy can reveal information about the atomic interactions in the gas, so glow discharges are used in plasma physics and analytical chemistry .
An electric light, lamp, or light bulb is an electrical component that produces light. It is the most common form of artificial lighting . Lamps usually have a base made of ceramic , metal, glass, or plastic which secures the lamp in the socket of a light fixture , which is often called a "lamp" as well.
Some of the least pleasant light comes from tubes containing the older, calcium halophosphate phosphors (chemical formula Ca 5 (P O 4) 3 (F, Cl):Sb 3+, Mn 2+). This phosphor mainly emits yellow and blue light, and relatively little green and red. In the absence of a reference, this mixture appears white to the eye, but the light has an ...
Instead of increasing current levels, luminance is usually increased by combining multiple LEDs in one bulb. Solving the problem of efficiency droop would mean that household LED light bulbs would need fewer LEDs, which would significantly reduce costs. Researchers at the U.S. Naval Research Laboratory have found a way to lessen the efficiency ...
Like all incandescent light bulbs, a halogen lamp produces a continuous spectrum of light, from near ultraviolet to deep into the infrared. [23] Since the lamp filament can operate at a higher temperature than a non-halogen lamp, the spectrum is shifted toward blue, producing light with a higher effective color temperature and higher power ...