Biology Chapter 2

  1. What are the essential elements?
    Carbon, Hydrogen, Oxygen, and Nitrogen
  2. What makes up 96% of living matter?
    The essential elements
  3. A substance consisting of two or more elements combined in a fixed ratio
    A compound
  4. Has characteristics different from those of its elements
    A compound
  5. Anything that takes up space and has mass
  6. Substances that cannot be broken down to other substances by chemical reactions
  7. What are organisms composed of?
  8. What is matter made up of?
  9. Are required by an organism in only minute quantities
    Trace elements
  10. What does an elements properties depend on?
    The structure of its atoms
  11. Consists of a certain kind of atom that is different from those of other elements
    Each element
  12. The smallest unit of matter that still retains the properties of an element
    An atom
  13. Atoms of each element are composed of even smaller parts called..
    Subatomic particles
  14. Relevant subatomic particles
    Neutrons, Protons, Electrons
  15. Have no electrical charge
  16. Are positively charged
  17. Are negatively charged
  18. Are found in atomic nucleus
    Protons and neutrons
  19. Surround the nucleus in a cloud
  20. Atoms of various elements differ in their number of..
    subatomic particles
  21. The atomic number is..
    • The number of protons
    • (unique to each element)
  22. The sum of protons plus neutrons in the nucleus of an atom
    The mass number of an element
  23. Differ in the number of neutrons and have the same amount of protons
  24. Spontaneously give off particles and energy
    Radioactive isotopes
  25. Vary in the amount of energy the possess
    An atoms electrons
  26. The capacity to cause change
  27. The energy that matter posseses because of its location or structure
    Potential energy
  28. Are reperesented by electon shells
    Energy levels
  29. Defined by its electron configuration and distribution
    The chemical behavior of an atom
  30. In the outermost, or valence shell of an atom
    Valence electrons
  31. Determine the chemical behavior of an atom
    Valence electrons
  32. The three-dimensional space where an electron is found 90% of the time
    An orbital
  33. The sharing of a pair of valence electrons
    A covalent bond
  34. Consists of two or more atoms held together by covalent bonds
    A molecule
  35. The sharing of one pair of valence electrons
    A single bond
  36. The sharing of two pairs of valence electrons
    A double bond
  37. The attraction of a particular kind of atom for the electrons in a covalent bond
  38. The more electronegative an atom..
    The more strongly it pulls shared electrons toward itself
  39. When the atoms have similar electronegativities and share electrons equally
    Nonpolar covalent bond
  40. When the atoms have differing electronegativities and share the electrons unequally
    Polar covalent bond
  41. An attraction between anions and cations
    Ionic bond
  42. Sometimes strip electrons away from their bonding partners
    Ionic bonds
  43. Electron transfer between two atoms creates..
  44. Atoms with more or fewer electrons than usual
  45. Negatively charged ions
  46. Positively charged ions
  47. Often called salts, which may form crystals
    Ionic compounds
  48. Forms when a hydrogen atom covalently bonded to one electronegative atom is also attracted to another electronegative atm
    A hydrogen bond
  49. Occur when transiently positve and negative regions of molecules attract each other
    Van der Waals interactions
  50. Reinforce the shapes of large molecules and help molecules adhere to each other
    Weak chemical bonds
  51. Is determined by the positions of its atoms valence orbitals and is usually very important to its function in the living cell
    The precise shape of a molecule
  52. Determines how biological molecules recognize and respond to one another with specificity
    Molecular shape
  53. The making and breaking of chemical bonds
    Chemical reactions
  54. Leads to changes in the compostion of matter
    Chemical reactions
  55. Convert reactants to products
    Chemical reactions
  56. An example of a chemical reaction:
  57. Is reached when the forward and reverse reaction rates are equal
    Chemical equilibruim
Card Set
Biology Chapter 2