definitions Chem exam 1

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definitions Chem exam 1
2013-10-03 02:02:53

Definitions chem 1
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  1. Measurement
    Quantative observation with a value number and a unit
  2. Scientific Notation
    standard way of expressing large as well as small numbers
  3. Significant Figures
    (digits) (sf) reflects precision of a given number
  4. Exact number
    Number with unlimited (Sf)
  5. Unit
    standard agreed upon quantities by which measurements are made  

    (eng & metric unit) (Scientist us SI units)
  6. Metric system
    uses prefixes multipliers to change the magnitude the size of units
  7. Length
    is a measure of distance between two points- measured with a ruler
  8. Volume
    is a measure of a 3dimensional space occupied by an object

    measured using graduated cylinder
  9. Mass
    is a measure of quantity of material (matter) 

    measured with balance
  10. Weight
    is a measure of force of gravity acting upon an object
  11. Unit conversion
    changing from one unit to another for particular measurements

    using conversion factors derived form equivalents
  12. Density
    is a measure of a mass per volume 

    the ratio of mass to volume
  13. D=    
    • D= m/v
    • M= d*v
    • V=m/d
  14. Matter
    is anything which has mass and occupies space

    consists of small particles like atom + molecules
  15. Energy
    is the ability to do work
  16. Atom
    is the smallest indivisible particle of any matter
  17. Molecule
    is a smaller particle with groups of atoms bond together
  18. Element
    is a substance which consists of same kind of atoms.

  19. Compound
    is a substance which consists of more than one kind of atoms bounded together

    • (heteroatomic) 
    • matter, molecule, element & compound
  20. Chemistry
    is a branch of science which studies matter to the molecular level
  21. Scientific method
    systematic way of learning through experiment and observation
  22. Hypothesis
    • is a tenative explanation based on observation
    • (can be modified)
  23. Scientific theory
    • is a well established hypothesis
    • (can be modified with time)

    which provides broader and deeper explanation based on many similar observations
  24. Atomic theory
    Atom is the smallest indivisible particle (small unit) of any matter
  25. Scientific Law
    statements given based on many similar observation with no exceptions to the rule 

    (can not be modified with time)
  26. Law of conservation
    Matter can neither be created nor destroyed.
  27. Solid
    • Particles that have definite (fixed) shape + volume
    • Incompressible
  28. Liquid
    Particles that have no fixed shape but have fixed volume

  29. Gas
    particles that do not have definite shape of volume

    Highly compressible
  30. Pure substance
    is a substance of consisting of same type of particles
  31. Element
    is a pure substance consisting of same type of atoms, which can not be broken down to simpler substances
  32. Compound
    is a pure substance consisting of particles, which is a chemical combination of two or more elements in a fixed ratio

    can be broken down to simpler substance
  33. Mixture
    is a physical combination of two or more substances with no fixed ratio

    Consists of more than one type of particle (atom + molecules)
  34. Hemogeneous Mixture
    uniform mixture of two or more substances whose composition is same through all different regions

    Air, Alloys, soda, sea water, alcoholic drinks
  35. Heterogeneous Mixture
    Non uniforms mixture of two or more substances, whose composition is not same through different regions.

    Milk, blood, oil + water, sand + water, paint
  36. Physical properties
    are characteristics exhibited with no change in composition (no new particles formed)

    viscosity, boiling point, freezing point

  37. Chemical properties
    are characteristics exhibited with a change in composition - New particles formed

    acidity, toxicity, flammability, corrosiveness

  38. Mixture of insoluble solid + liquid
    Heterogeneous Mixture

    sand + water
  39. Mixture of soluble solid + water
    Homogeneous Mixture

    sodium chloride + water
  40. Mixture of two liquids which are miscible (mixed very well)
    Homogeneous Mixture

    Alcohol + water
  41. Mixture of two liquids which are immiscible (do not mix)
    Heterogeneous Mixture 

    oil + water
  42. Energy
    is ability to work
  43. Law of conservation of energy
    Energy can neither be created or destroyed
  44. Potential energy
    is the stored form of energy

    is the energy of particle at rest
  45. Kinetic Energy
    is the energy of a moving particle
  46. calorie
    is the amount of energy required by one gram of water to change by 1 degree celcius
  47. Temperature
    is a measure of intensity of heat 

    measurement related to the relative movement of particles 

    measured using a thermometer
  48. Specific heat capacity
    is the amount of energy required by one gram of a substance to change by 1 degree celcius
  49. Heat
    is the thermal energy exchanged due to temperature differences
  50. Exothermic
    energy released, given out, lost, is a product
  51. Endothermic
    energy absorbed, gained, taken in is a reactant
  52. Atom:
    is the smallest particle (single unit) of any matter
  53. Electrons
    are lighter negatively charged particle found within an atom

    Symbol e1-
  54. Protons
    are heavier positively charged particles found in the heavy center core of the atom called the nucleus 

    symbol p1+
  55. Neutrons
    are as heavy as a proton 

    symbol n0
  56. Subatomic particles
    particles found within an atom

    what are they, scientist, exp, model/theory, symbol, relative charge, relative mass, location
  57. Atomic number
    stands for the number of protons

    # of electron
  58. Mass number
    stands for the total number of protons + neutrons 

    dont mistake with atomic mass
  59. amu- atomic mass unit
    is equal to 1/12th the mass of carbon-12 which has 6 protons and 6 neutrons
  60. Isotopes
    are atoms of the same element with different mass number

    are atoms of the same element with different number of neutrons
  61. Atomic mass of an element
    is the average relative isotopic mass of all the isotopes of a given element
  62. Isotopic abundance
    is the extent to which an isotope is available in nature
  63. Natural abundance
    all isotopes are not present to the same extent
  64. Symbols of elements
    are with one or two letters derived form english, latin or greek names of elements
  65. Mendeleev
    Father of periodic table
  66. Periodic law
    when elements arranged by increasing relative atomic mass sets of properties of elements recur periodically
  67. Modern Periodic table
    elements are arranged by increasing atomic number
  68. Ions
    are charged particles formed by the loss or gain of electrons
  69. Positvie ion
    Cation-is formed by the loss of electron by metallic element
  70. Negative ion
    is formed by the gain of the electrons by non metallic elements
  71. Noble gas Rule
    Main group elements tend to lose or gain electrons to become stable like nearest noble gas