1. Which of the following elements is NOT one of the six that make up 98% of most organisms' body weight?

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• 1. Which of the following elements is NOT one of
  the six that make up 98 of most organisms' body
  weight?
• A. hydrogen B. nitrogen C. carbon D. iron

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2

• 2. All atoms of a certain element have the same
  number of protons.
• True False

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3

• 3. All matter is composed of certain basic
  substances called elements.
• True False

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4

• 4. The three isotopes of carbon 12C, 13C and 14C
  have different numbers of _______?
• A. electrons B. protons C. neutrons

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5

• 5. Protons have a __________ electrical charge.
• A. positive B. negative C. neutral

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6

• 6. Electrons always have the same amount of
  potential energy.
• True False

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7

• 7. The atomic number of an atom is the same as
  __________.
• A. the atom's mass B. the number of protons the
  atom has C. the number of neutrons the atom has

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8

• 8. If an atom has an atomic number of 17 and an
  atomic mass of 35, the number of neutrons in its
  nucleus equals _____.
• A. 17 B. 18 C. 35 D. 52

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9

• 9. Electrons with the least amount of potential
  energy are located in the __________ shell.
• A. L B. K C. M

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10

• 10. If an atom with an atomic number of 9 and an
  atomic mass of 19 is electrically neutral, it has
  __________ electrons.
• A. 9 B. 10 C. 19 D. 28

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• 11. Radioactive isotopes are used to __________.
  
• A. determine the age of fossils B. trace
  chemicals during biochemical reactions C. detect
  thyroid abnormalities D. all of the above

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12

• 12. Electrons that are farther from the nucleus
  have more potential energy than electrons closer
  to the nucleus.
• True False

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13

• 13. The subatomic particle with an atomic mass
  of one and a neutral charge is a(n) __________.
• A. proton B. electron C. neutron

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14

• 14. The nucleus contains ________.
• A. protons B. electrons C. neutrons D. A and C

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• 15. Electron shells, other than the first one,
  can contain up to eight electrons.
• True False

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16

• 16. An electrically neutral atom with an atomic
  number of 7 will have _____ electron shell(s).
• A. one B. two C. three D. four

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• 17. Electrically neutral magnesium (atomic
  number 12) is an example of an inert (non
  reactive) atom.
• True False

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18

• 18. How many carbon atoms are there in a
  molecule of glucose, C6H12O6?
• A. 1 B. 6 C. 12 D. 24

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19

• 19. If a chemical equation is balanced, there
  are equal numbers of each specific atom on both
  sides of the arrow.
• True False

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20

• 20. An atom of hydrogen (atomic number 1
  atomic mass 1) has one proton and no neutrons.
• True False

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21

• 21. Which of the following is an inert
  (non-reactive) atom?
• A. hydrogen atomic number 1 B. oxygen atomic
  number 8 C. neon atomic number 10 D.
  chlorine atomic number 17

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22

• 22. The sodium ion (Na) has 12 protons (atomic
  number of Na 11).
• True False

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23

• 23. Which bond is most easily broken?
• A. a hydrogen bond B. a triple covalent bond C.
  a single covalent bond

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24

• 24. What type of bond is formed when atoms share
  electrons?
• A. ionic B. covalent C. hydrogen

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25

• 25. Chlorine (atomic number 17) needs _____
  electron(s) to fill its outermost electron shell.
  
• A. no B. one C. seven D. eight

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26

• 26. Electrically neutral atoms are called ions.
• True False

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27

• 27. In a __________ covalent bond, two atoms
  share two pairs of electrons.
• A. single B. double C. triple

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28

• 28. An equal sharing of electrons creates a
  __________ bond.
• A. polar covalent B. ionic C. hydrogen D.
  non-polar covalent

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29

• 29. Which of the following is most likely to
  form an ionic bond with Cl-?
• A. F- B. Na C. He D. O2

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30

• 30. Which of the following is an example of a
  compound?
• A. O2 B. Na C. CO2 D. Ne

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31

• 31. What type of bond will form between 2 atoms
  of nitrogen (atomic number 7) to form the gas
  N2?
• A. ionic B. triple covalent C. single covalent
  D. none

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32

• 32. An atom with one electron in its outermost
  shell tends to be an electron donor.
• True False

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33

• 33. A dashed line between atoms represents a(n)
  _____ bond.
• A. hydrogen B. single covalent bond C. ionic
  D. polar covalent bond

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34

• 34. The chlorine ion (Cl-) has 17 protons and 18
  electrons.
• True False

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35

• 35. The three dimensional shape of a molecule
  affects its ability to function.
• True False

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36

• 36. Hydrogen bonds form when ___________.
• A. atoms share electrons B. a slightly negative
  atom is attracted to a slightly positive atom C.
  atoms gain electrons D. atoms lose protons

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37

• 37. Energy is __________.
• A. required for a bond to form B. released when
  a bond is broken C. A and B

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38

• 38. An attraction between oppositely charged
  atoms forms a _____ bond.
• A. polar covalent B. triple covalent C.
  hydrogen D. ionic

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39

• 39. The atom with greater electronegativity will
  have a slight positive charge in a polar covalent
  bond.
• True False

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40

• 40. Water is a polar molecule.
• True False

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• 41. A negative ion _____.
• A. has accepted an electron from another atom B.
  is radioactive and can be used to determine the
  age of fossils C. will form a polar covalent
  bond with another atom D. all of the above

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42

• 42. The calcium ion (Ca2) _____.
• A. has accepted two protons B. has given away
  two electrons C. will form a covalent bond with
  the chlorine ion (Cl-) D. all of the above

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43

• 43. Water molecules are _____.
• A. polar B. hydrogen bonded to one another C.
  cohesive D. all of the above

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44

• 44. Internal body fluids are kept at a near
  neutral pH by buffers.
• True False

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45

• 45. A pH of 7 is _____.
• A. acidic B. basic C. neutral

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46

• 46. Which of the following has a basic pH?
• A. lemon juice B. milk of magnesia C. tomatoes
  D. hydrochloric acid

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47

• 47. Hydrogen bonding ___________.
• A. causes water molecules to cling to each other
  B. allows water to absorb a lot of heat without
  a huge change in temperature C. must be broken
  to convert water to steam D. all of the above

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• 48. All living things are _____ water.
• A. less than 10 B. 10-30 C. 40-60 D. 70-90

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49

• 49. Which property of water is attributed to its
  polarity?
• A. It resists changes in temperature. B. It has
  a high surface tension. C. It is the universal
  solvent. D. It is less dense as a solid than as
  a liquid.

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• 50. Which property of water is responsible for
  facilitating the flow of water upwards in a tree?
  
• A. It resists changes of state (from liquid to
  ice or liquid to steam). B. It is cohesive and
  adhesive. C. It is the universal solvent. D. It
  is less dense as a solid than as a liquid.

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51

• 51. Molecules that attract water are described
  as hydrophilic.
• True False

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52

• 52. Aquatic living things are able to survive
  the winter thanks to which property of water?
• A. It is less dense as a solid than as a liquid.
  B. It is cohesive and adhesive. C. It is the
  universal solvent D. It resists changes of state
  (from liquid to ice or liquid to steam).

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53

• 53. Which of the following is best described as
  hydrophobic?
• A. water B. oil C. sugar D. salt

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54

• 54. Water would still freeze at 0C and boil at
  100C without hydrogen bonding.
• True False

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55

• 55. A solution with a pH of 5 has 10 times more
  hydrogen ions (H) than a solution with a pH of
  6.
• True False

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56

• 56. Any pH below _____ is acidic.
• A. one B. five C. seven D. twelve

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57

• 57. Acid rain is a problem because ___________.
• A. it adversely affects fish living in lakes B.
  it weakens trees by leaching away nutrients C.
  it damages marble and limestone buildings and
  monuments D. all of the above

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58

• 58. Sulfur dioxide and nitrogen oxides combine
  with atmospheric water to produce sulfuric acid
  and nitric acid which falls to earth as acid
  rain.
• True False

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59

• 59. Which of the following is an example of an
  acid?
• A. HCl B. NaCl C. NaOH D. CO2

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60

• 60. Water is less dense at 4C than at 0C which
  is why water freezes from the bottom upwards.
• True False

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