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40 Cards in this Set
- Front
- Back
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Excitation
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a system (such as an atom, molecule or nucleus) is any quantum state of the system that has a higher energy than the ground state (that is, more energy than the absolute minimum). The temperature of a group of particles is indicative of the level of excitation.
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Electron
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a subatomic particle that carries a negative electric charge. It has no known components or substructure, and therefore is believed to be an elementary particle.
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Frequency
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is the number of occurrences of a repeating event per unit time
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Energy
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is a quantity that can be assigned to every particle, object, and system of objects as a consequence of the state of that particle, object or system of objects.
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Plancks Constant
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is a physical constant used to describe the sizes of quanta of action in quantum mechanics, specifically as angular momentum in the atomic structure. It is named after Max Planck, one of the founders of quantum theory. It is an important proportionality constant when describing atoms and the photons of electromagnetic radiation
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Photon
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is an elementary particle, the quantum of the electromagnetic interaction and the basic "unit" of light and all other forms of electromagnetic radiation. It is also the force carrier for the electromagnetic force. The effects of this force are easily observable at both the microscopic and macroscopic level, because the photon has no rest mass; this allows for interactions at long distances.
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Emission Spectra
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a chemical element or chemical compound is the relative intensity of each frequency of electromagnetic radiation emitted by the element's atoms or the compound's molecules when they are returned to a ground state.spectroscopy can be used to identify the elements in matter of unknown composition
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Spectroscope
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is an instrument used to measure properties of light over a specific portion of the electromagnetic spectrum, typically used in spectroscopic analysis to identify materials. The variable measured is most often the light's intensity but could also, for instance, be the polarization state. The independent variable is usually the wavelength of the light or a unit directly proportional to the photon energy, such as wavenumber or electron volts, which has a reciprocal relationship to wavelength
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spectral line
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is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from an excess or deficiency of photons in a narrow frequency range, compared with the nearby frequencies
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Incandescence
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is the emission of light (visible electromagnetic radiation) from a hot body due to its temperature.
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absorption spectra
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refers to spectroscopic techniques that measure the absorption of radiation, as a function of frequency or wavelength, due to its interaction with a sample. The sample absorbs energy, i.e., photons, from the radiating field. The intensity of the absorption varies as a function of frequency, and this variation is the absorption spectrum. Absorption spectroscopy is performed across the electromagnetic spectrum.
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Fluorenscence
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the emission of electromagnetic radiation light by a substance that has absorbed radiation of a different wavelength. In most cases, absorption of light of a certain wavelength induces the emission of light with a larger wavelength (and lower energy). However, under conditions in which intense radiation is being absorbed, it is possible for one electron to absorb two photons (multiple photon absorption), which can lead to the emission of radiation having a smaller wavelength than the excitation source.
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Fraunhofer Lines
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are a set of spectral lines named for the German physicist Joseph von Fraunhofer (1787–1826). The lines were originally observed as dark features (absorption lines) in the optical spectrum of the Sun.
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Mercury
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A heavy, silvery d-block metal, mercury is one of five metallic chemical elements that are liquid at or near room temperature and pressure
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Phosphor
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is a substance that exhibits the phenomenon of phosphorescence (sustained glowing after exposure to energized particles such as electrons or ultraviolet photons).
Phosphors are transition metal compounds or rare earth compounds of various types. The most common uses of phosphors are in CRT displays and fluorescent lights. |
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Filaments
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is a source of electric light that works by incandescence (a general term for heat-driven light emissions, which includes the simple case of black body radiation). An electric current passes through a thin filament, heating it to a temperature that produces light. The enclosing glass bulb contains either a vacuum or an inert gas to prevent oxidation of the hot filament. Incandescent bulbs are also sometimes called electric lamps, a term also applied to the original arc lamps.
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Phosphorescence
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a specific type of photoluminescence related to fluorescence. Unlike fluorescence, a phosphorescent material does not immediately re-emit the radiation it absorbs. The slower time scales of the re-emission are associated with "forbidden" energy state transitions in quantum mechanics. As these transitions occur less often in certain materials, absorbed radiation may be re-emitted at a lower intensity for up to several hours.
The study of phosphorescent materials led to the discovery of radioactivity in 1896 |
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Metastable state
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is a complex systems' concept describing the time-invariance of their state-describing parameters (coordinates and magnitudes of the spatial distributions of physical or informational quantitites). The 'metastable' states of a system have lifetimes (unchanged state-parameter values) lasting at least 100 times longer than the shortest lived of its states
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LASER
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Light amplification by stimulated emission of radiation (LASER or laser) is a mechanism for emitting electromagnetic radiation, typically light or visible light, via the process of stimulated emission. The emitted laser light is (usually) a spatially coherent, narrow low-divergence beam, that can be manipulated with lenses.
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monochromatic light
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is light of a single frequency, though in practice it can refer to light of a narrow frequency range.
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excited
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of a system (such as an atom, molecule or nucleus) is any quantum state of the system that has a higher energy than the ground state (that is, more energy than the absolute minimum). The temperature of a group of particles is indicative of the level of excitation.
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energy levels
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system or particle that is bound, confined spatially, can only take on certain discrete values of energy, as opposed to classical particles, which can have any energy
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Kinetic Energy
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is the extra energy which it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its current velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes
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Atom
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a basic unit of matter consisting of a dense, central nucleus surrounded by a cloud of negatively charged electrons. The atomic nucleus contains a mix of positively charged protons and electrically neutral neutrons (except in the case of hydrogen-1, which is the only stable nuclide with no neutron). The electrons of an atom are bound to the nucleus by the electromagnetic force
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Coherent light
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is a property of waves that enables stationary (i.e. temporally and spatially constant) interference. More generally, coherence describes all properties of the correlation between physical quantities of a wave.
When interfering, two waves can add together to create a larger wave (constructive interference) or subtract from each other to create a smaller wave (destructive interference), depending on their relative phase. Two waves are said to be coherent if they have a constant relative phase. The degree of coherence is measured by the interference visibility, a measure of how perfectly the waves can cancel due to destructive interference. |
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Quantization
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is the process of explaining a classical understanding of physical phenomena in terms of a newer understanding known as "quantum mechanics". It is a procedure for constructing a quantum field theory starting from a classical field theory. This is a generalization of the procedure for building quantum mechanics from classical mechanics.
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Luminescence
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light that usually occurs at low temperatures, and is thus a form of cold body radiation. It can be caused by chemical reactions, electrical energy, subatomic motions, or stress on a crystal. This distinguishes luminescence from incandescence, which is light generated by high temperatures
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Ultraviolet
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is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than x-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV. It is so named because the spectrum consists of electromagnetic waves with frequencies higher than those that humans identify as the color violet.
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Bioluminescence
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he production and emission of light by a living organism. Its name is a hybrid word, originating from the Greek bios for "living" and the Latin lumen "light". Bioluminescence is a naturally occurring form of chemiluminescence where energy is released by a chemical reaction in the form of light emission. Adenosine triphosphate (ATP) is involved in most instances. The chemical reaction can occur either inside or outside the cell.
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Thomas Young
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was an English genius and polymath, admired by, among others, Herschel and Einstein. He is famous with the public for having partly deciphered Egyptian hieroglyphs before Jean-Francois Champollion did.
Young made notable scientific contributions to the fields of vision, light, solid mechanics, energy, physiology, language, musical harmony and Egyptology. |
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Double-slit Experiment
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Young's experiment) demonstrates the inseparability of the wave and particle natures of light and other quantum particles. A coherent light source illuminates a thin plate with two parallel slits cut in it, and the light passing through the slits strikes a screen behind them. The wave nature of light causes the light waves passing through both slits to interfere, creating an interference pattern of bright and dark bands on the screen. However, at the screen, the light is always found to be absorbed as though it were made of discrete particles, called photons
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Classical Mechanics
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is one of the two major sub-fields of study in the science of mechanics, which is concerned with the set of physical laws governing and mathematically describing the motions of bodies and aggregates of bodies geometrically distributed within a certain boundary under the action of a system of forces.
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Quantum Theory
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et of scientific principles describing the known behavior of energy and matter that predominate at the atomic and subatomic scales. The name derives from the observation that some physical quantities—such as the angular momentum of an electron—can be changed only by set amounts, or quanta, rather than being capable of varying by any amount. The wave–particle duality of energy and matter at the atomic scale provides a unified view of the behavior of particles such as photons and electrons. Photons are the quanta of light, and have energy values proportional to their frequency via the Planck constant. An electron bound in an atomic orbital has quantized values of angular momentum and energy. The unbound electron does not exhibit quantized energy levels, but is associated with a matter wave, as are all massive particles. The full significance of the Planck constant is expressed in physics through the dynamic physical attriubute of action
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Planck
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was a German physicist. He is considered to be the founder of the quantum theory, and thus one of the most important physicists of the twentieth century. Planck was awarded the Nobel Prize in Physics in 1918In 1894 Planck turned his attention to the problem of black-body radiation. He had been commissioned by electric companies to create maximum light from lightbulbs with minimum energy. The problem had been stated by Kirchhoff in 1859: how does the intensity of the electromagnetic radiation emitted by a black body (a perfect absorber, also known as a cavity radiator) depend on the frequency of the radiation (i.e., the color of the light) and the temperature of the body?
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I Love You
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Good luck on your test love, I know you'll do great :-*
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Newton
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built the first practical reflecting telescope[7] and developed a theory of colour based on the observation that a prism decomposes white light into the many colours that form the visible spectrum. He also formulated an empirical law of cooling and studied the speed of sound.
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Maxwell
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demonstrated that electricity, magnetism and even light are all manifestations of the same phenomenon: the electromagnetic field. From that moment on, all other classic laws or equations of these disciplines became simplified cases of Maxwell's equations. Maxwell's work in electromagnetism has been called the "second great unification in physics",[3] after the first one carried out by Isaac Newton.
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Photoelectric effect
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phenomenon in which electrons are emitted from matter (metals and non-metallic solids, liquids or gases) as a consequence of their absorption of energy from electromagnetic radiation of very short wavelength, such as visible or ultraviolet light. Electrons emitted in this manner may be referred to as "photoelectrons".[1][2] As it was first observed by Heinrich Hertz in 1887,[2] the phenomenon is also known as the "Hertz effect",[3][4] although the latter term has fallen out of general use. Hertz observed and then showed that electrodes illuminated with ultraviolet light create electric sparks more easily.
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Millikan
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was an American experimental physicist, and Nobel laureate in physics for his measurement of the charge on the electron and for his work on the photoelectric effectworked on an oil-drop experiment (since repeated, with varying degrees of success, by generations of physics students) in which they measured the charge on a single electron.
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Photon
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an elementary particle, the quantum of the electromagnetic interaction and the basic "unit" of light and all other forms of electromagnetic radiation. It is also the force carrier for the electromagnetic force. The effects of this force are easily observable at both the microscopic and macroscopic level, because the photon has no rest mass; this allows for interactions at long distances. Like all elementary particles, photons are governed by quantum mechanics and will exhibit wave-particle duality – they exhibit properties of both waves and particles
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