Chemistry Unit 5 Exam

  1. atomic number
    number of protons in nucleus
  2. mass number
    sum of the protons and neutrons in the nucleus
  3. problems with Dalton's Modern Atomic Theory
    • atoms are divisible
    • not all atoms of an element have the same mass
  4. Thomson
    • cathode rays:
    • have a charge
    • have magnetism
    • are beam of particles, not energy
  5. Thomson model
    plum pudding model
  6. Rutherford
    • an atom is mostly empty space 
    • discovered nucleus
    • mass located in center
  7. Milikan
    charge of electron
  8. Chadwick
  9. Planck
    electromagnetic energy = quantized
  10. Bohr
    • Electrons orbit a nucleus
    • allowed states
  11. What has to occur for an electron to transfer energy levels?
    the electron has to either gain or release the exact energy difference between the two levels it is moving between
  12. Schrodinger
    • quantum model
    • fixed the energy of an electron
  13. Proton defines 
  14. Electron defines
  15. What force holds a nucleus together?
    strong force
  16. What force attract electrons to nucleus?
    electrostatic attractions
  17. Which is a greater attraction? 
    Strong force or Electrostatic attraction
    strong force
  18. average atomic mass
    the weighted average mass of all isotopes of an element
  19. atomic mass unit (amu)
    1/12 the mass of a carbon-12 atom
  20. Hund's rule
    every orbital in a subshell is singly occupied with one electron before any one orbital is doubly occupied, and all electrons in singly occupied orbitals have the same spin.
  21. 1A
    alkali metals
  22. 2A
    Alkaline earth metals
  23. 6A
  24. 7A 
  25. 8A
    noble gases
  26. group 1A-7A
    representative elements
  27. How are elements arranged in the periodic table?
    increasing atomic number
  28. How did Mendeleev arrange the elements on the periodic table?
    increasing atomic mass
  29. period
    (left to right)
  30. what does a period represent?
    principal energy level
  31. group
  32. what does a group represent?
    elements with similar properties and reactivities
  33. metals (4)
    • make up most of elements
    • good conductors of electricity
    • solids at room temp (except mercury)
    • ductility and malleability
  34. nonometals (4)
    • most are gases at room temp
    • opposite of metals
    • poor conductors
    • brittle
  35. as we move away from the nucleus, the hold on any electrons ________.
  36. as we move toward the nucleus, the hold on any one electron ______
  37. effective nuclear charge
    average charge each electron feels
  38. effective nuclear charge _____ across a period
  39. atomic radius
    • period: decreases
    • -b/c electrons are pulled closer to the nucleus due to increasing enc
    • group: increases
    • -inclusion of additional levels
  40. cation
    net positive charge of an atom
  41. anion
    net negative charge of an atom
  42. oxidation state
    charge of an ion after gaining/losing electrons
  43. cations are _____ than parent atoms
  44. ionization energy is..
    the energy required to remove an electron from the atom
  45. anions are _____ than their parent atoms.
  46. first ionization energy
    • period: increases
    • due to increased enc
    • group: decreases
    • -decreased proximity of the electrons to the nucleus
  47. electronegativity is...
    ability of an atom in a molecule to attract electrons
  48. electronegativity
    • period: increases
    • -increased enc
    • group: decreases
    • -due to decreased proximity of the electrons to the nucleus
  49. Energy or Wavelength =
    • E =hc       or      λ=hc
    •        λ                     E
  50. Energy =
  51. C =
Card Set
Chemistry Unit 5 Exam
chem unit 5 cumulative review cards: scientists, subatomic particles,