Science vocab #2

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Science vocab #2
2013-05-29 21:19:54

Flash cards for science class
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  1. Galaxy
    • Huge collection of stars, planets, and dust that is held together by gravity.
  2. Star Cluster
    • Collection of stars held together by gravity
  3. Globular Cluster
    • Collection of 1000-1000000 stars, arranged in a spherical shape, around center of milky way.
  4. Local group
    • Group of about 40 galaxies including the Milky Way.
  5. Super Cluster
    • Gigantic cluster of 4-25 clusters of galaxies, hundreds of millions of light-years in size.
  6. Cosmology
    • The study of the universe.
  7. Doppler Effect
    • Change in frequency of a light source due to its motion relative to an observer.
  8. Red Shift
    • Effect in which objects moving away from an observer have their wavelengths lengthened, towards red end of a visual spectrum.
  9. Blue Shift
    • Objects moving towards an observer have their wavelengths shortened, towards the blue end of a visual spectrum.
  10. Big bang
    • Event that may have triggered the expansion of the universe, 14 billion years ago.
  11. Cosmic Microwave Background Radiation
    • Radiation left over from the big bang, which fills the universe.
  12. Electricity
    Form of energy that results from the interaction of charged particles, such as electrons and protons.
  13. Static Electricity
    An electric charge that stays on the suface of an object, rather than flowing away quickly.
  14. Charging by friction
    Process in which objects made from different materials rub together, producing a net static charge on each object.
  15. Electrostatic series
    A list of materials that have been arranged according to their ability to hold onto electrons.
  16. Insulator
    A material in which electrons cannot move easily from one atom to another.
  17. Conductor
    A material in which electrons can move easily between atoms.
  18. Semiconductor
    A material in which electrons can move fairly well between atoms.
  19. Ground
    Object that can supply a very large number of electrons to, or can remove a very large number of electrons from, a charged object, thus neutralizing that object.
  20. Electroscope
    A device for detecting the presence of an electric charge.
  21. Charging by contact
    Generating a net charge on a neutral by touching it with a charged object.
  22. Laws of electricity
    Laws that describe how two objects interact when 1 or both are charged.
  23. Electric field
    A property of the space around a charged object, where the effect of its charge can be felt by other objects.
  24. Induced charge seperation
    The movement of electrons in a substance, caused by the electric field of a nearby charged object that is not in direct contact with the substance.
  25. Ion
    A positively or negatively charged atom or group of atoms.
  26. Lightning rod
    A metal sphere or point that is attached to the highest point of a building and connected to the ground.
  27. Vander Graff generator
    A device that accumulates very large charges.
  28. Electrostatic precipitator
    A type of cleaner that removes unwanted particles and liquid droplets from a flow of gas.
  29. Radiation dosimeter
    A small device that detects and measures exposure to radiation.
  30. terminal
    A position on a cell that must be connected to other components to form a circuit.
  31. Switch
    A control device that can complete or break the circuit to which it is connected
  32. Open Circuit
    A circuit that contains a gap or break
  33. Closed circuit
    A circuit where electrons can flow through the complete circuit.
  34. Electric current
    A measure of the number of charged particles that pass by a point in the electric circuit each second.
  35. Coulomb
    The quantity of charge that is equal to 6.25x1018
  36. Ampere
    The unit of electric current, equivalent to one coulomb per second.
  37. Electrical resistance
    The property of a substance that hinders electric current and converts electrical energy to other forms of energy.
  38. Resistor
    A device used in an electric  circuit to reduce the current through a component by a specific amount.
  39. Load
    A resistor or any other device that transform electrical energy into heat, motion, sound, or light.
  40. Potential Difference (Voltage)
    The difference between the electric potential energy per unit of charge at two points in a circuit.
  41. Volt (V)
    The unit for potential difference equivelant to one joule (J) per coulomb (C).
  42. Circuit Diagram
    A diagram that uses standard symbols to represent the components in an electrical circuit and their connections.
  43. Series Circuit
    A circuit in which there is only one path along which electrons can flow.
  44. Parallel Circuit
    A circuit in which there is more than on path along which electrons can flow.
  45. Electric circuit
    A closed path along which electrons that are powered by an energy source can flow.
  46. Voltaic cell
    A source of energy that generates an electric current by chemical reactions involving two different meals or metal compounds separated by a conducting solution.
  47. Battery
    A connection of two or more cells.
  48. Electrode
    One of two metal terminals in a cell or battery.
  49. Electrolyte
    A solution or paste that conducts charge.
  50. Dry cell
    A cell that contains an electrolyte made of paste.
  51. Wet cell
    A cell that contains a liquid electrolyte.
  52. Primary Cell
    A cell that can be used only once.
  53. Secondary Cell
    A cell that can be recharged.
  54. Fuel cell
    A cell that generates electricity through the chemical reactions of fuel that is stored outside the cell.
  55. Terminal
    A position on a cell that must be connected to other components to form a circuit.
  56. Switch
    A control device that can complete or break the circuit to which it is connected.
  57. Open Circuit
    A circuit that contains a gap or break.
  58. Closed Circuit
    A complete circuit that electrons can flow through completely.
  59. Ohm's law
    The ratio of potential difference to current is a constant called resistance.
  60. Ohm
    The unit for resistance, equivalent to one volt per ampere (V/A).
  61. Superconductor
    A material through which electric charge can flow with no resistance
  62. Non Ohmic
    Not following Ohm's law.
  63. Direct current
    Current in which charged particles travel through a circuit in only one direction.
  64. Alternating Current (AC)
    A current in which electrons move back and forth in a circuit.
  65. Transformer
    An electrical device that changes the size of the potential difference of an alternating current.
  66. Circuit breaker
    A safety device that is placed in series with other circuits that lead in appliances and outlets.
  67. Fuse
    A safety device that is found in older buildings and some appliances, like a circuit breaker, it is placed in series with other circuits that lead to appliances and outlets.
  68. Electrical power
    The rate at which an appliance uses electrical energy.
  69. Watt (W)
    A unit of electrical power: 1 kilowatt=1000 W.
  70. Kilowatt (kW)
    A practical unit of electrical power: 1 kW=1000 W.
  71. Electrical energy
    The energy that is used by an appliance at a given setting: Is determined by multiplying its power rating by the length of time it is used.
  72. Kilowatt-hour
    The practical unit of electrical energy.
  73. Smart meter
    A meter that records the total electrical energy used hour by hour and sends this information to the utility company automatically.
  74. Time of use pricing
    A system of pricing in which the cost of each kW.h of energy used is different at different times of the day.
  75. Phantom Load
    The electricity that is consumed by an appliance or device when it is turned off.
  76. Efficiency
    The ratio of useful energy output to total energy input, expressed as a percentage.
  77. Base load
    The continuous minimum demand for electrical power.
  78. Hydroelectric power generation
    The production of electricity using a source of moving water.
  79. Intermediate load
    A demand for electricity that is greater than the base and is meet by burning coal and natural gas.
  80. Peak load
    The greatest demand for electricity, which is met by using hydroelectric power and natural gas.
  81. Renewable energy source
    A source of energy that can be replaced in a relatively brief period of time.
  82. Wind Farm
    Many large wind turbines at one location.
  83. Solar energy
    Energy that is directly converted from the energy of the Sun into electricity.
  84. Photovoltanic cell
    The generation of a direct current when certain materials are exposed to light.
  85. Biomass energy
    Any organic materials that can be burned and used as a source of fuel.
  86. Matter
    • Anything that has mass and occupies space
  87. Pure Substance
    • Matter that contains only one kind of particle.
  88. Mixture
    • Matter that contains more than one kind of particle
  89. Element
    • A pure substance that cannot be broken down into simpler parts by chemical methods
  90. Compound
    • A pure substance made up of two or more different types of elements that are chemically combined.
  91. Physical property
    • A characteristic of a substance that can be observed and measured without changing the identity of the substance.
  92. viscosity
    • The measure of a substances resistance to flow.
  93. melting point
    • The temperature at which a solid turnes into a liquid.
  94. boiling point
    • the temperature at which a liquid turns into a gas.
  95. solubility
    • A measure of the ability of a substance o dissolve in another substance.
  96. density
    • The ratio of the mass of a substance to the volume it occupies.
  97. chemical property
    • The ability of a substance to change or react, and to form new substances.
  98. combustibility
    • The ability of a substance to burn in air.
  99. stability
    • The ability of a substance to remain unchanged
  100. toxicity
    • The ability of a substance to cause harmful effects in plants and animals.
  101. atom
    • The smallest particle of an element that retains the identity of the element.
  102. Electron
    • A negatively charged particle within the atom.
  103. Subatomic Particle
    • A particle that is smaller than the atom.
  104. Nucleus
    • In chemistry, the positively charged centre of an atom.
  105. Proton
    • A positively charged particle that is part of every atomic nucleus
  106. Neutron
    • An uncharged particle that is part of almost every atomic nucleus
  107. Atomic number
    • the number of protons in the nucleus of an atom.
  108. Mass number
    • The sum of the number of protons and the number of neutrons in the nucleus of an atom
  109. Isotope
    • One of two or more forms of an element that have the same number of protons but a different number of neutrons.
  110. Atomic Mass
    The average mas of the naturally occuring isotopes of an element
  111. Periodic Table
    • A system for organizing the elements into columns and rows, so that elements with similar properties are in the same column.
  112. Metal
    • Typically, an element that is hard, shiny, malleable, and ductile, and is a good conductor of heat and electricity.
  113. Non-Metal
    • Typically, an element that is not shiny,malleable, or ductile, and is a poor conductor of heat and electricity.
  114. Metalloid
    • An element that shares some properties with metals and some properties of non-metals.
  115. Period
    • A horizontal row of elements in the periodic table.
    • *note:there is not enough room left to include pictures in the remainder of the definitions
  116. Group
    A vertical column of elements in the periodic table.`
  117. Valence Electron
    An electron in the outermost occupied energy level of an atom.
  118. ion
    A positively or negatively charged atom or group of atoms.
  119. chemical bond
    A chemical link between two atoms, which holds the atoms together.
  120. ionic bond
    A chemical bond that forms between oppositely charged ions.
  121. Ionic compound
    A compound made of oppositely charged ions.
  122. Molecular Compound
    A compound with particles made up of atoms held together by covalent bonds.
  123. Covalent Bond
    A chemical bond in which two atoms share one or more pairs of electrons.
  124. Molecule
    The smallest discrete particle of a molecular compound; has one or more shared pairs of electrons in one or more covalent bonds.