H Chem: Unit 2

  1. matter
    anything that takes up space and displays the properties of mass and inertia
  2. inertia
    a resistance to change
  3. composition
  4. properties
    distinguishable qualities or attributes of a sample of matter
  5. liquid
    a state of matter in which the bonds can be rearranged, broken, and reformed repeatedly, the volume is fixed but the substance takes the shape of its container
  6. solid
    a state of matter in which there is a fixed volume and shape, the atoms don't move much and are packed tightly together
  7. gas
    a state of matter in which the bonds of the atoms are broken and nonexistent, there is no fixed volume or shape, conforms to whatever volume available
  8. saline
    salt water
  9. mixture
    does not have a definite composition, where things are mixed but not chemically bonded or changed, can be separated by physical means
  10. pure substance
    things such as elements and compounds that are chemically bonded and have a definite composition, has a fixed chemical formula that can only be separated by chemical means
  11. solution
    a homogenous mixture
  12. solute
    in a solution, the stuff that gets dissolved (usually has the lowest volume in the mixture)
  13. solvent
    in a solution, the substance that does the dissolving (usually has the highest volume in the mixture)
  14. atom
    the smallest unit of matter
  15. subatomic particles and their symbols
    • protons p+
    • neutrons no
    • electrons e-
  16. element
    a type of atom that has a specific number of subatomic particles; cannot be broken down into other substances by chemical methods
  17. atomic number
    number that tells how many protons an atom has
  18. molecules
    two or more atoms covalently bonded together, does not include ions (ionic bonds)
  19. atomic bond
    the exchange or sharing of electrons
  20. physical properties
    a characteristic not related to change; things like odor, color, volume, state, density, melting point and boiling point
  21. chemical properties
    the ability of a substance to change
  22. electrolysis
    decomposition of water by an electric current, a chemical process
  23. physical change
    a change that does not produce a new substance, involves a change in one or more physical properties
  24. chemical change
    a change that produces a new substance with new properties
  25. reaction
    the occurrence of a chemical change
  26. compound
    a substance composed of a given combination of elements that can be broken down into those elements by chemical methods, has at least two different types of atoms
  27. homogeneous mixture
    mixture that is the same throughout
  28. heterogeneous mixture
    mixture where the regions may have different properties
  29. distillation
    separating the ingredients of a mixture by boiling water and causing the solid components to e left behind
  30. filtration
    using a mesh to have the liquid separate from the solid ad leave behind the solid remnants
  31. types of physical properties
    intensive and extensive
  32. intensive properties
    do not depend of amount of matter present
  33. extensive properties
    depend on the amount of matter that is present (e.g. volume, mass, size, shape)
  34. precipitate
    to form an insoluble compound either by reacting two salts or by changing the temperature to affect solubility; name of solid formed by precipitation reaction
  35. phase
    the state of matter that a substance is in
  36. alloy
    a substance made by melting two or more elements together, at least one of them a metal
  37. steam
    the gaseous phase of water
  38. uniform throughout
    means that any sample of the substance will have the same properties and appearance
  39. cation
    a positive ion; an atom where there are more protons than electrons
  40. anion
    a negative ion; an atom where there are more electrons than protons
  41. mass number
    a sum of the protons and neutrons in an atom
  42. atomic mass
    the average of the masses of the known isotopes of an atom
  43. isotope
    an atom with the same number of protons but different number of neutrons; has a different mass because it has a different number of neutrons
  44. carbon's isotopes, which is more common
    carbon 12 (more abundant), carbon 14
  45. fusion
    putting atoms together
  46. group
    the vertical columns of the periodic table (there are 18), where elements have similar properties
  47. the elements in the periodic table are arranged in order of increasing ?
    atomic number
  48. basic classification of elements in the periodic table
    metals, metalloids, non-metals
  49. atomic number representation
  50. ions are produced when an atom loses or gains ?
  51. separation techniques of mixtures
    filtration, distillation, gas-liquid chromatography
  52. decomposition techniques of mixtures
    heat, electrolysis
  53. periodic law
    when elements are arranged by increasing z (atomic number), properties repeat periodically
  54. period
    the rows in the periodic table, there are seven
  55. family in group 1
    alkali metals (excludes H)
  56. family in group 2
    alkaline earth metals
  57. family in group 18
    noble gases
  58. family in group 17
  59. metalloid line
    star-step line in the periodic table that separates metals from non-metals
  60. protons
    subatomic particles located in the atom's nucleus with a positive charge, have mass
  61. neutrons
    subatomic particles located in an atom's nucleus, have no charge, have mass
  62. electrons
    subatomic particles located in the electron cloud which surrounds the nucleus, have negative charge, have virtually no mass
  63. neutral atom
    aka free atom; an atom where the number of protons and electrons are the same, overall charge is zero
  64. reactants
    the substances present before a reaction
  65. products
    the substances present after a reaction
  66. law of constant composition
    a given compound has the same composition (ratio of elements), regardless of where it comes from
  67. Dalton's atomic theory
    • elements are composed of atoms
    • atoms in an element are the same
    • different atoms can combine to form compounds (compounds have a definite composition)
    • atoms cannot be chemically destroyed, but they can be chemically rearranged
  68. chemical formula
    something that expresses the types and numbers of atoms in each unit (molecule) of a given compound
  69. element symbol
    the abbreviation of the element's name, like Na
  70. main elements
    elements in group 1A-8A, all elements excluding the transition metals
  71. person who first formed the periodic table
  72. nuclear decay
    particles within the nucleus breaking down and/or being released
  73. most dangerous form of nuclear decay
    gamma rays
  74. radiation
    mass and energy
  75. relationship between mass and energy
    less mass = more energy and vice versa
  76. half life
    the amount of time required for one half of the original mass to decay
  77. half life equation
    • fraction remaining = (1/2)n
    • mass remaining=(original mass)(fraction remaining)
    • n= total time elapsed/ half life time
  78. how many elements are known, and how many occur naturally?
    116; 88
  79. Robert Boyle
    the first scientist generally accredited with putting the study of chemistry on a firm experimental basis
  80. which are heavier: neutrons or protons?
    neutrons are slightly heavier
  81. are all of the atoms in an element the same?
    no, the neutrons can vary
  82. metalloid
    an element that has some properties common to both metallic and nonmetallic elements
  83. alpha decay representation
    4/2 He
  84. beta decay representation
    0/-1 e
  85. positron emission decay representation
    0/+1 e
  86. are substance composed of one type of atom
  87. the mass of one atom of an element based on the average of all known isotopes
    atomic mass number
  88. the spontaneous decomposition of a nucleus
  89. a substance composed of only one type of atom
  90. two or more elements chemically joined
  91. a substance that cannot be broken down chemically into a simpler substance
  92. smallest particle of an element with all the properties of that element
  93. region of atom where protons and neutrons are found
  94. a shorthand used to represent elements
  95. a compound must
    contain atoms of different elements and be chemically combined in a definite proportion
  96. T/F: elements and compounds are always pure substances
Card Set
H Chem: Unit 2