BI 253 Chapter 2

  1. Define Matter
    Anything that takes up space & has mass
  2. What is an element?
    Substance that can not be broken down to other substances by chem reactions
  3. What 4 elements make up about 96% of human body weight?
    Oxygen, Carbon, Nitrogen, Hydrogen
  4. What % of body is composed of Oxygen?
  5. What % of body is composed of Carbon?
  6. What % of body is composed of Nitrogen?
  7. What % of body is composed of Hydrogen?
  8. What 7 elements make up approx 4% of body weight?
    Calcium, Phosphorus, Potassium, Sulfur, Sodium, Chloride, Magnesium
  9. What elements are found in the body in trace amts (<0.01%)
    • Boron
    • Chromium
    • Cobalt
    • Copper
    • Fluorine
    • Iodine
    • Iron
    • Manganese
    • Molybdenum
    • Selenium
    • Silicon
    • Tin
    • Vanadium
    • Zinc
  10. What is a molecule?
    A combination of atoms of the same or different elements
  11. Define a compound.
    Molecule of different elements mixed in different ratios
  12. An atom is . . . .
    The smallest unit of all physical matter.
  13. What is a proton, where is it located & what is its mass?
    Positively charged particle in the nucleus w/ a mass of 1
  14. What is a neutron, where is it located & what is its mass?
    A particle w/ no charge, located in nucleus w/a mass of 1
  15. What is an electron, where is it located & what is its mass?
    Negatively charged particle that surrounds nucleus & has negligible mass
  16. What is the atomic #?
    # that defines the # of protons in an element
  17. What comprises the atomic mass?
    The # of protons & neutrons
  18. Explain a chemical symbol.
    1 or 2 letter shorthand for the name of the element
  19. What are isotopes?
    Atom w/ same # of protons as original but diff # of neutrons
  20. Describe a radioisotope.
    Unstable isotope that gives off energy in form of radiation.
  21. What is an orbital?
    Series or electron shells or energy levels around the nucleus.
  22. What is the outermost electron shell called & what does it determine?
    • Valence Shell
    • Determines how the atom will react with other atoms
  23. Explain the octet rule.
    States that atoms w/ >3 electrons want to have 8 in their Valence Shell
  24. A stable atom has ___ e‾ in its valence. These naturally occur in ___ ___.
    • 8
    • Noble Gases
  25. An unstable atom has ____ e⁻ in its valence & wants to bond to form ____.
    • Unpaired
    • Molecules
  26. What 3 ways can atoms satisfy the octet rule?
    • Gain e⁻ fr other atoms
    • Lose e⁻ to other atoms
    • Share e⁻ w/other atoms
  27. Describe a non-polar covalent bond.
    Shares e⁻ equally between atoms
  28. Describe a polar covalent bond.
    Shares e⁻ unequally & relies on electronegativity to stay together
  29. What are 2 characteristics of Ionic Bonds?
    • Complete transfer of e⁻
    • Rely on electronegativity
  30. Give 3 characteristics of a covalent bond.
    • Strongest of all bonds
    • Requires a lot of energy to break
    • Very Stable
  31. Define electronegativity.
    Attractive force an atom exerts on e⁻
  32. What determines electronegativity?
    # of p⁺ in an atom & distance of e⁻ fr nucleus
  33. Describe an ionic bond.
    e⁻ transferred fr 1 atom to another forming pos or neg ions which are attracted to each other
  34. Positively charged ions are called ___.
  35. Negatively charged ions are called ____.
  36. What is a complex or polyatomic ion?
    Grp of covalently bonded atoms that carry a charge
  37. Oxidation is the. . . .
    Loss of 1 or more electrons
  38. Reduction is the . . . .
    Gain of 1 or more electrons
  39. LEO the lion says GER means what?
    • Lose Electrons Oxidized
    • Gain Electrons Reduced
  40. Where does a hydrogen bond exist?
    Between an electronegative atom & a hydrogen atom bonded to another electronegative atom
  41. ___ ___ ALWAYS involves a hydrogen atom
    Hydrogen Bonding
  42. Hydrogen Bonds are stronger than ___ ___ but weaker than ___ & ___ bonds
    • Van der Waals Forces
    • Covalent & Ionic
  43. Give 3 places were hydrogen bonds exist for our purposes.
    • Water
    • DNA base pairs
    • Proteins
  44. Explain Van der Waals Interactions.
    Attractions between molecules that are close together as a result of hot spots of pos or neg charge
  45. What are chemical reactions?
    The making and breaking of chem bonds
  46. What are reactants?
    Raw materials or Ingredients in a chem reaction
  47. What are products?
    Finished product in a chem reaction
Card Set
BI 253 Chapter 2
Chapter 2 9-13