10/5/12

  1. An _____ is the smallest particle that has all the properties of an element
    Atom
  2. The center of the atom is called the _____.
    Nucleus
  3. particle accelerators =
    atom smashers
  4. The 3 primary constituents of an atom is the _____, the _____, and the _____.
    • electron
    • proton
    • neutron
  5. The electron, proton & neutron are considered the _____ _____
    fundamental particles
  6. ** The fundamental particles of an atom are the _____. the _____, and the _____.
    • electron
    • proton
    • neutron
  7. Electrons are very small particles that carry one unit of _____ electric charge
    negative
  8. Because an atomic particle is extremely small, its mass is expressed in _____ _____ _____ for convenience
    atomic mass units
  9. One AMU is equal to _____ the mass of a carbon-12 atom 
    1/12
  10. When precision is not necessary,a system of whole numbers called_____ _____ _____ is used.
    atomic mass numbers
  11. The atomic mass number of an electron is _____.
    zero
  12. The nucleus contains particles called _____, of which there are 2 types: protons & neutrons.  Both have nearly 2000 times the mass of an electron
    nucleons
  13. The atom is essentially _____ space
    empty
  14. The number of protons determines the ______ ______
    chemical elements
  15. Atoms that have the same number of protons but differ in the number of neutrons are _____; they behave the same way during chemical reactions
    isotopes
  16. Electrons can exist only in certian _____, which represents different _____ ______ ______ or energy levels.
    • shells
    • electron binding energies
  17. In their normal state atoms are electrically neutral; the electric charge on the atom is _____.
    zero
  18. If an atom hhas an extra electron or has had an electron removed, it is said to be _____.
    ionized
  19. Note: Ionization is the removal or addition of an orbital elctron from an atom
  20. Note: The atom is essentially empty space
  21. The fundamental particles of an atom are the electron, the proton, and the neutron
  22. The maximum number of electrons that can exist in each shell increases with the distance of the shell from the _____.
    nucleus
  23. maximum electrons per shell can be calculated by :
    2nsquared
  24. Note: No outer shell can contain more than 8 electrons
  25. ______ force is the force that keeps an electron in orbit
    Centripetal
  26. Note: The force that keeps an electron in orbit is the centripetal force
  27. _____ force is the firce that causes an electron to travel straight and leave the atoom.
    Centrifugal
  28. ______ forces make sure the electrons maintain their distance from the nucleus while traveling in a circular path
    Centrifugal
  29. The strength of attachment of an electron to the nucleus is called the _____ _____ _____
    electron binding energy
  30. The closer an electron is to the nucleus, the more _____ it is bound.
    • tightly
    • K shell electrons have higher binding energies than L-shell electrons. L more than M and so forth
  31. Note: An Atomic Mass Number and the precise mass of an atom are not equal
  32. The characterics mass of an element, the _____ _____, is determined by the relative abundance of isotopes and their respective atomic masses
    elemental mass
  33. Note: Isotopes: Atoms that have the same atomic number but different atomic mass numbers are isotopes.
  34. Atoms that have the same atomic number but different atomic mass numbers are ______.
    isotopes
  35. Atomic nucleui that have the same atomc number but different atomic mass numbers are _______.
    Isobars
  36. Atoms that have the same number of neutrons but different numbers of protons are _____.
    Isotones
  37. What has the same atomic number and the same atomic mass number
    Isomer
  38. one method of association to help with the is definitions is:
    Isotope - same proton
    Isobar - same a
    Isotone - same neutron
    isomer - metastable
  39. Note:
    Molecule -  Atoms of various elements may coombine to form structures called molecules
  40. note:
    Compund - A chemical compound is any quanity of one type of molecule
  41. Note: **
    The smallest particle of an element is an atom, the smallest particle of a compund is a molecule.
  42. ** Some atoms exist in an abnormally excited state characterized by an unstable nucleus.
    To reach stability the nucleus spontaneously emits particles and energy and tranforms itself into another atom.
    This process is called radioactive disintegration or radioactive decay
  43. Atoms of variuos elements may combine to form structures called _______?
    Molecules
  44. A chemical compund is any quanity of one type of molecule is a _____?
    Compound
  45. Hydrogen, oxygen, carbon and nitrogen compose more than _____% of the human body
    95%
  46. Water molecules make up approximately _____% of the human body
    80%
  47. Oxygen & hydrogen combine into water through what?
    covalent bonds
  48. THe smallest particle of an element is an ____; the smallest particle of a compound is a _____.
    • atom
    • molecule
  49. To reach stability the nucleus spontaneously emits particles and energy and transforms itself into another atom is a process called _____ _____.
    • radioactive disintegration
    • radioactive decay
  50. Any nuclear arrangement is called a _____.
    nuclide
  51. Note: Radioactivity is the emission of particles and energy in order to become stable.
  52. Note: Radioactice decay results in emission of alpha particles, beta particles, and usually gamma rays.
  53. Note: Half Life- The halflife of a radioisotope is the time required for a quanity of radioactivity to be reduced to one-half its orgiinal value
  54. _____ is the emission of particles and energy in order to become stable
    Radioactivity
  55. In addition to stable isotope, many elements have radioactive isotopes or radioisotopes. These mat be artifically produced in machines such as particles accelerators or _____ _____.
    nuclear reactors
  56. Radioisotopes can decay to stability in many ways but two _____ emission and _____ emission, are important here for descriptive purposes.
    • beta
    • alpha
  57. Radioactive matter is not here one day and gone to the next.
    Rather, radioisotopes disintegrate into stable isotopes of different elements at a decreasing rate so that the quanity of radioactive material never quite reaches zero
  58. The _____ _____ of a radioisotope is the time required for a quanity of radioactivity to be reduced to one-half its orignal value
    half life
  59. All ionizing radiation can be conveniently classified into 2 categories: _____ radiation and _____ radiation.
    • particulate
    • electromagnetic
  60. There are 2 maiin types of particulate radiation: _____ particles and _____ particles.
    Both are associated with radioactive decay.
    • alpha
    • beta
  61. The _____ particles is equivelent to a helium nucleus. It contains 2 protons and 2 neutrons. Its mass is approximately 4 amu and it carries 2 units of positive electric charge
    alpha
  62. _____ particles have a is quickly lost and has a short range in matter
    alpha
  63. Positive beta particles are _____.
    positrons
  64. note: Beta particules differ from apha particles in terms of mass and charge.
    They are light particles with an atomic mass number of zero and carry one unit of negative or positive charge. THe only difference between electrons and negative beta particles is their origin.
  65. An alpha particle is a helium nucleus that contains ___ protons and ___ neutrons
    • 2
    • 2
  66. A beta particle is an electron emitted from the nucleus of a _____ atom.
    radioactive
  67. _____ & _____ are forms of electromagnetic ionizing radiation
    xrays & gamma rays
  68. x-rays & gamma rays are often called ______.
    photons
  69. ______ have no mass and no charge
    photons
  70. _____ travel at the speed of light and are considered energy disturbances in space.
    photons
Author
sandy2696
ID
175164
Card Set
10/5/12
Description
PHYSICS CHAPTER 2
Updated