H Chem: Unit 3

  1. speed of light
    c=3.00 x 108 m/sec
  2. wavelength
    lamda, nm; the distance from crest to crest of adjacent waves
  3. frequency
    nu, Hertz; the # of waves that pass through a point per unit of time
  4. velocity
    v, m/sec
  5. energy
    E, Joules (J)
  6. Planck's constant
    h=6.626 x 10-34 Jsec
  7. basic properties of electrons
    • can move a lot because they're almost massless
    • have properties of waves and can be measured like them
  8. dual nature
    electrons have two behaviors, of particles and waves
  9. correlation of wave size and energy
    • small wave=little energy
    • big wave=a lot of energy
  10. amplitude
    height of the wave from the baseline to the crest
  11. equilibrium position
    the line that crosses the waves horizontally that divides it equally up and down
  12. correlation of frequency and wavelength
    • lowest frequency=longest wavelength
    • highest frequency=shortest wavelength
    • inversely related
  13. ROY G BIV
    • a mneumonic device for memorizing the colors of the visible electromagnetic spectrum
    • red orange yellow green blue indigo violet
  14. electromagnetic spectrum
    describes the range of energy that does not need a medium to travel through
  15. quantum numbers
    • describe how electrons fit in atoms and how they are arranged
    • represent an aspect of electrons' positions, but only describes the nature
  16. what are the four quantum numbers
    • principle quantum number (n)
    • angular momentum quantum number (l)
    • magnetic quantum number (m)
    • electron spin quantum number (s)
  17. principle quantum number (n)
    describes energy levels, can range from 1-7 like the periods
  18. difference between energy levels
    • low energy level will be small, close to the nucleus, and low in energy
    • high energy level will be large, further from the nucleus, and higher in energy
  19. speed of electron movement
    speed of light, c
  20. relation of distance from nucleus and energy amount
    electrons further from the nucleus will have more energy
  21. angular momentum quantum number (l)
    describes the shape of orbitals, that each energy level can be made up of s, p, d, and/or f
  22. how many orbitals or shapes are in each of the angular momentum quantum numbers (l)
    • s= one
    • p= three
    • d= five
    • f= seven
  23. how to know how many orbitals are in each energy level
    use the periodic table, the energy level corresponds to the period, and you can see which blocks (s, p, d, f) are included in which periods, and you know how many orbitals represent each layer
  24. maximum number of electrons that can fit in each angular momentum quantum number (l)
    • s= 2e
    • p= 6e
    • d= 10e
    • f= 14e
  25. each shape/orbital can hold ? electrons
  26. photon
    stream of tiny packets of energy
  27. correlation of photon energy and wavelengths
    longer wavelengths=lower photon energy
  28. orital
    probability map for an electron, decreases as the electron gets further away from the nucleus
  29. principle energy levels and sublevels
    • synonymous with principle quantum number (n) and angular momentum quantum number (l)
    • there are seven energy levels, and these are divided into certain shapes of oritals
  30. s, p, d, and f shapes
    • s= sphere
    • p= double lobe
    • d= clover (double, double lobe)
    • f= multiple wacky shapes
  31. magnetic quantum number (m)
    describes their orientation in space, how it is arranged in 3D
  32. electron spin quantum number (s)
    • describes the spin of the electron in its shape cloud; in each shape cloud there are 2 electrons, and they have equal but opposite movement
    • spin values are +1/2 and -1/2, means up/down
  33. the main group elements are in the ? block(s)
    s and p
  34. the group number in the main elements represents ?
    # of valence electrons
  35. electron configuration: numbers that go before the angular movement quantum numbers
    • for any s or p blocks, n=row#
    • for d block, n=row-1
    • for f block, n=row-2
  36. waves travel at the speed of light in what context
  37. shorthand method of electron configuration
    • find the previous noble gas, put its symbol in [brackets], then configure from its point on
    • this can show you the number of valence electrons (associated with highest n)
  38. law of constant composition
    • a given compound always contains the same proportions (by mass) of the elements
    • elements will always be in the same ratio/composition
  39. Dalton's atomic theory
    • elements are made of atoms
    • all atoms of a give element are identical
    • the atoms of one element differ from the atoms of a different element
    • atoms of different elements combine to form compounds, consistent in composition
    • atoms don't break up in chemical processes, no atom is created nor destroyed
  40. use of Dalton's atomic theory
    predict how a pair of elements could form different kinds of compounds
  41. J.J. Thomson
    • found electrons and reasoned that there must be positive particles as well
    • known for finding electrons
  42. Lord Kelvin/William Thomson
    • plum pudding model of the atom, uniform composition, enough positive and negative particles to balance out the charge
    • known for his plum pudding model
  43. Ernest Rutherford
    • found positively charged alpha particles
    • did the beam test and found that they bounced off of a thin metal at different angles
    • reasoned that the positive particles were small and in the center, dense, and the rest was empty space
    • known for finding neutrons
  44. nuclear atom
    Rutherford's name for an atom with a dense center of positive charge (nucleus), with electrons around it and empty space
  45. Rutherford's atom model
    • protons and neutrons in the small center, surrounded by electrons and a lot of empty space
    • charge of atom is balanced and electrons move around the nucleus
  46. Bohr model of the atom
    • hydrogen has a small positive nucleus with electrons orbiting it
    • thought there were energy levels like rings
    • thought electrons could jump from levels by emitting or absorbing photons of energy
  47. Victor + chrodinger's findings
    light has wave and particle characteristics, and so do electrons
  48. wave mechanical model
    • electrons are in orbitals that do not precisely describe the electrons' movements/paths
    • shows the probability of where electrons go
  49. beginning of the atom theory
    Democritus described matter in terms of atoms which were indivisible
  50. laws of definite composition
    • each substance has its own chemical formula, definite formula
    • e.g. H2O, all water has this ratio
  51. law of multiple proportion
    • elements may combine in various proportions with each other
    • e.g. water and oxygen can combine like H20 or H2O2
  52. excited state
    unstable, unmaintainable state of electrons after photon absorption
  53. ground state
    normal energy state of electrons
  54. continuous spectrum
    • a spectrum that represents a continuous array¬† of energy throughout mediums, no blank spots
    • e.g. the electromagnetic spectrum
  55. emission spectrum
    the colors that you see being bounced off, the thin slices of energy that are not asborbed
  56. valence electrons
    electrons in the outermost energy level
  57. metals always form ?
    positive ions, never negative ions
  58. what are the main elements likely to form
    • group 1A- +1 ions
    • group 2A- +2 ions
    • group 3A- +3 ions
    • group 4A- unpredictable
    • group 5A- -3 ions (except metals)
    • group 6A- -2 ions
    • group 7A- -1 ions
    • group 8A- noble gases, very stable
  59. the area in an atom where electrons are most likely to be found is called the
    electron cloud
  60. how to find the number of valence electrons
    use shorthand electron configuration method, count all of the electrons in the highest energy level
  61. ? are never valence
  62. John Dalton
    known for Dalton's atomic theory, and the idea that elements are made up of indivisible atoms
  63. Hund's rule
    in angular momentum quantum numbers, electrons fill up orbitals and THEN they pair up, so unpaired electrons are electrons in orbitals which are alone
  64. Pauli exclusion principle
    an atomic orbital can hold a maximum of 2 e-s, and those electrons have opposite spins
  65. stable orbitals
    • full or half full orbitals
    • energy levels with more electrons
  66. how can you tell from a valence orbital diagram that an atom is in its excited state
    electron(s) will jump from a previous orbital into the next orbital, the second to last orbital will be missing an electron and it will be in the next spot(s)
  67. isoelectronic
    atoms with the same number of electrons and therefore the same configurations
  68. ionization energy
    the quantity of energy required to remove an electron from the gaseous atom or ion
  69. metals/nonmetals ? have lower ionization energies
  70. atomic size
    atomic radius, how large the atom is, the measurement of a line drawn between of the two centers of atoms
  71. crystalline state
    freezing something in a gaseous state so that it will turn into a solid and you can measure fixed points (in the nucleus)
  72. relation of atomic radius and group and why
    • as you move from top to bottom, atomic radius increases
    • number of energy level increases and therefore outermost e-s are further from nucleus
  73. relation between atomic radius and period and why
    • as you move from left to right (across a period), atomic radius decreases
    • atomic number increases and the larger number of protons increases the atom's ability to hold e-s close so atomic size decreases
  74. first, second, third, etc. ionization energy
    the amount of energy required to remove one, two, three, etc. electrons in succession from an atom
  75. relation between ionization energy and group and why
    • as you move from top to bottom in a group, first ionization energy decreases
    • electrons close to the nucleus are harder to remove because the nucleus pulls them more, and electrons get further away from the nucleus with higher energy levels
  76. relation between ionization energy and periods and why
    • as you move from left to right (across a period), ionization energy generally increases
    • as the number of valence electrons increases, it becomes better to just add electrons than to subtract them in order to achieve a full or half full valence orbital status
  77. what is the acronym for remembering the atomic radius trend
    LLL- larger lower left
  78. ionization energy trend exceptions
    pattern not true when an element could be full or half full, or having just one full letter orbital
  79. shielding
    • electrons closer to the nucleus shield outer electrons from nuclear forces, the attraction of the nucleus is shielded
    • therefore it is easier to remove electrons in the outer orbitals and ionization energy is less
  80. electronegativity
    the attraction of an atom fro the electrons of another atom
  81. most electronegative element and why
    Fluorine, only needs one more electron to fill its valence orbital and it has a small energy level so shielding does not take effect
  82. ion radius
    the size of the ion
  83. which ions have a higher ion radius
    negative ions are bigger than positive ions in general
  84. relation between group/period and electronegativity
    increases across a group (from left to right) and decreases from top to bottom
  85. correlation of frequency and energy
    higher frequency = higher energy
  86. electromagnetic radiation and its speed
    any form of energy in the electromagnetic spectrum that travels at the speed of light
  87. what is observed when salts of Na+1, Cu+2, or Li+1 are heated in a flame
  88. an atom at lowest possibly energy state is said to be at ? state
  89. when an atom in an excited state and it returns to ground state, what happens to the excess energy of the atom
  90. differences between 1s and 2s orbitals
    more energy in 2s, further away from nucleus, bigger
  91. similarities between 1s and 2s
    one orbital, can hold up to 2 e-s, spherical shape
Card Set
H Chem: Unit 3