Bio Chapter 2

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Bio Chapter 2
2014-02-11 01:20:36
Bio 181

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  1. What is a Covalent Bond?
    The sharing of a pair of valence e- by two atoms!
  2. Two or more atoms held together by covalent bonds constitute a ___?_____.
  3. Electronegativity?
    Attraction of a particular atom for the e- of a covalent bond
  4. The more electro-negative an atom is, the more _____ it pulls ______electrons toward itself
    strongly! shared!!
  5. What is an element?
    a substance that cannot be broken down to other substances by chemical reactions
  6. What is a compound?
    Consists of two or more different elements combined in a fixed ratio
  7. Atom?
    smallest unit of matter that still retains the props of an element
  8. mass number?
    sum of protons and neutrons
  9. atomic number?
  10. isotope?
    same element different # of neutrons
  11. What is an ion?
    a Charged atom or molecule
  12. positively charged ions have more +p or -e?
  13. What are the most abundant elements occurring in our body?
    O, C, H and N
  14. 4 elements that make most of our body mass?

    also give percentage.
    • -Oxygen 65.0%
    • -Carbon 18.5%
    • -Hydrogen 9.5%
    • -Nitrogen 3.3%
  15. Other elements that make up our body mass (~3.7%) ?
    • Ca
    • P
    • K
    • S
    • Na
    • Cl
    • Mg
  16. What does oxygen do for our bodies?
    • -Found in water
    • -Found in blood and lungs due to respiration
  17. Some things that does carbon does for our bodies?
    • -found in organic molecules in our body
    • -Typically ingested in food that is eaten
  18. Hydrogen in our body?
    Hydrogen is found in all water molecules in the body as well as many other compounds making up the various tissues
  19. Nitrogen in our bodies..?
    -Very common in proteins and organic compounds.
  20. Some things Ca does for humans?
    Calcium is a primary component of the skeletal system, including the teeth. It is also found in the nervous system, muscles, and the blood.
  21. Some things P does for us humans
    This element is common in the bones and teeth, as well as nucleic acids.
  22. Some things K does for our body?
    Potassium is found in the muscles, nerves, and certain tissues
  23. Some things Na does for our bodies?
    Sodium is excreted in sweat, but is also found in muscles and nerves
  24. Some things Cl does for our body?
    Chlorine is present in the skin and facilitates water absorption by the cells.
  25. Some things Mg does for our body?
    Magnesium serves as a cofactor for various enzymes in the body.
  26. Some things S does in our body?
    Sulfur is present in many amino acids and proteins.
  27. Some things Iron does for our body?
    Iron is found mostly in the blood since it facilitates the transportation of oxygen.
  28. Some things Iodine does in our body?
    Iodine is found in certain hormones in the thyroid gland.
  29. What are radioactive isotopes?
    Isotope in which the nucleus decays spontaneously,  giving off particles and energy.

    Changes atom to an atom of a different element.
  30. What is an electron shell?
    Where electrons can be found
  31. Atoms with completed valence shell are said to be unreactive or _________.
  32. The 3 dimensional space where an e- is found 90% of the time is called?
    An orbital
  33. How many electrons can fill and orbital?
  34. What are the two most strongest kinds of chemical bonds?
    covalent and ionic bonds