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  1. Trace elements are thoserequired by an organism in only minute quantities. Which of the following is atrace element that is required by humans and other vertebrates?
  2. Which of the followingstatements is false?
    Protons and electrons are electrically chargedparticles. Protons have one unit of negative charge, and electrons have oneunit of positive charge.
  3. Each element is unique anddifferent from other elements because of the number of protons in the nuclei ofits atoms. Which of the following indicates the number of protons in an atom'snucleus?
    atomic number
  4. The mass number of anelement can be easily approximated by adding together the number of ____ in anatom of that element.
    protons and nuetrons
  5. What is the approximateatomic mass of an atom with 16 neutrons, 15 protons, and 15 electrons?
    31 daltons (add electrosn and neutrons ex. 16 + 15)
  6. Oxygen has an atomic number of 8 and a mass number of 16. Thus, the atomic mass of an oxygen atom is
    approximatly 16 Daltons (mass # = atomic mass)
  7. The nucleus of a nitrogen atom contains 7 neutrons and 7 protons. Which of the following is a correct statement concerning nitrogen?
    The nitrogen atom has a mass number   of 14 and an atomic mass of approximately 14 daltons.
  8. An atom with an atomic number of 9 and a mass number of19 would have an atomic mass of approximately
    19 daltons
  9. isotopes                                                                      
    • are variation os the same element, ex. atom 1 has a mass number of 31 and atom 2 has a mass number of 32.
    • atoms with different mass number but identical atomic numbers
  10. One difference between carbon-12  and carbon-14  is that carbon-14 has
    2 more nuetrons than carbon 12
  11. 3H is a radioactive isotope of hydrogen. One difference between hydrogen-1 ( 1/1H ) and hydrogen-3 ( 3/1H) is that hydrogen-3 has
    2 more nuetrons than hydrogen 1
  12. Two isotopes of the sameelement will have different numbers of
  13. when drawing the electron configuration of an element
    look and count its atomic number. ex. neon has an atomic number of 10 so its electron configuration should have 10 dots in total.
  14. Valence electrons
    are the empty spaces on the outer shell of an elements electron configuration.
  15. What does the reactivity ofan atom depend on?
    presence of unpaired electrons in the outervalence shell of the atom
  16. Atoms whose outer electron shells contain eight electrons tend to
    be stable and chemically nonreactive, or inert.
  17. What are the chemical properties of atoms whose valence shells are filled with electrons?
    • They form covalent bonds inaqueous solutions.
    • They exhibit similarchemical behaviors
  18. What is the maximum numberof electrons in the 1s orbital of an atom?
  19. What is the maximum numberof electrons in a 2p orbital of an atom?
  20. What is the maximum numberof covalent bonds an element with atomic number 8 can make with hydrogen?
  21. What results from anunequal sharing of electrons between atoms?
    a polar covalent bond
  22. A polar covalent bond can form when
    one of the atoms has a greater affinity for electrons than the other atom of the same molecule.
  23. cation
    positive ion, the one that has to share
  24. The ionic bond of sodium chloride is formed when
    chlorine gains an electron from sodium.
  25. Results from a transfer ofelectron(s) between atoms.
    ionic bond
  26. Explains most specificallythe attraction of water molecules to one another.
    hydrophobic interaction
  27. Which of the following istrue for this reaction?                     3 H2 + N2 <==>  2 NH3
    Hydrogen and nitrogen are the reactants of thereverse reaction.
  28. Which of the following describes any reaction that has attained chemical equilibrium?
    Both the forward and the reverse reactions havestopped with no net effect on the concentration of the reactants and theproducts.
  29. In a single molecule ofwater, the two hydrogen atoms are bonded to a single oxygen atom by
    polar covalent bonds.
  30. The slight negative chargeat one end of one water molecule is attracted to the slight positive charge ofanother water molecule. What is this attraction called?
    an ionic bond
  31. What do cohesion, surfacetension, and adhesion have in common with reference to water?
    All are properties related to hydrogen bonding.
  32. Which of the following is possible due to the high surface tension of water?
    A water strider can walk across the surface of asmall pond.
  33. Which of the following istrue when an ice cube cools a drink?
    Molecule collisions in the drink increase.
  34. Water's high specific heatis mainly a consequence of the
    absorption and release of heat when hydrogenbonds break and form
  35. Desert rabbits are adapted to the warm climate because their large ears aid in the removal of heat due to the a.high surface tension of water.
    high specific heat of water
  36. The formation of ice duringcolder weather helps moderate the seasonal transition to winter. This is mainlybecause
    the formation of hydrogen bonds releases heat.
  37. At what temperature iswater at its densest?
    4 degrees Celcius
  38. Ice is lighter and floats in water because it is a crystalline structure in which each water molecule is bonded to a maximum of four other water molecules by which kind of bond?
  39. Why does ice float inliquid water?
    Hydrogen bonds stabilize and keep the moleculesof ice farther apart than the water molecules of liquid water.
  40. Hydrophobic substances suchas vegetable oil are
    nonpolar substances that repel water molecules.
  41. One mole (mol) of asubstance is
    • 6.02 x 10 to the 23 molecules of the substance.
    • the molecular mass of thesubstance expressed in grams.
  42. How many molecules ofglycerol (C3H8O3) would be present in 1 L of a1 M glycerol solution?
  43. Recall that when sodiumchloride (NaCl) is placed in water the component atoms of the NaCl crystaldissociate into individual sodium ions (Na+) and chloride ions (Cl-).In contrast, the atoms of covalently bonded molecules (e.g, glucose, sucrose,glycerol) do not generally dissociate when placed in aqueous solution. Which ofthe following solutions would be expected to contain the greatest concentrationof particles (molecules or ions)?
    1.0 M NaCl
  44. How many grams of the molecule in the figure above would be required to make 2.5 L of a 1 M solution of the molecule?(Carbon = 12, Oxygen = 16, Hydrogen = 1)
    • 60
    • ex. multiply the carbon atomic number (12) by the number of carbons available. repeat then add the numbers together.
  45. Which of the following ionizes completely in solution and is considered to be a strong base?
  46. Which of the followingstatements is completely correct?
    H2CO3 is a strong acid,and NaOH is a strong base.
  47. A given solution contains0.0001(10-4) moles of hydrogen ions [H+] per liter. Whichof the following best describes this solution?
    acidic: H+ donor
  48. What would be the pH of asolution with a hydroxide ion [OH-] concentration of 10-12 M?
    pH 2
  49. Which of the followingsolutions has the greatest concentration of hydroxide ions [OH-]?
    seawater at pH 8
  50. If the pH of a solution is decreased from 9 to 8, it means that the
    • concentration of H+has increased 10 times what it was at pH 9.
    • concentration of OH-has decreased 10 times what it was at pH 9.
  51. If the pH of a solution isincreased from pH 5 to pH 7, it means that the
    concentration of OH- is 100 timesgreater than what it was at pH 5.
  52. One liter of a solution pH9 has how many more hydroxide ions (OH-) than 1 L of a solution ofpH 4?
    100,000 times more
Card Set:
2012-11-04 23:45:10
AP Biology terms

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