1. In scientific measurements, accuracy and precision are two different concepts.
2. The medicines, vitamins, sugar, and salt that we use are chemicals.
3. The law of conservation of energy does not apply to a burning candle because heat is generated.
4. The law of conservation of mass does not apply to a burning candle, because the candle is eventually burned out.
5. A scientific law is ALWAYS true under ALL conditions, on the earth or in the space.
6. A compound can be chemically broken down into two or more elements.
7. “Mixtures consist of a blend of two or more substances.”  Thus, ice water is a mixture.
8. Vapors are considered gases!
9. The most abundant element in weight in our body is carbon.
10. The oxygen gas we breath is written as “O”.
11. All gases are diatomic.
12. A water molecule (H₂O) is formed by reacting 1H₂ with 1O.
13. Iron melts at an extremely high temperature of 1534 °C, which is thus considered a chemical change.
14. A substance with a relatively high specific heat capacity would undergo a relatively large temperature change upon heating.
15. The calorie is a unit of heat energy.
16. When the temperature of equal masses of two different substances increases 5 °C, the substance with the lower specific heat capacity absorbs more energy.
17. No matter what ruler you are using, you can always give as many significant figures as you want to increase the accuracy of the measurements.
18. An electric balance can give very accurate measures of weight even without calibration.
19. You can obtain a set of data that have a very high accuracy, but a very low precision.
20. The metabolism of sugar in our body changes the sugar molecules in the solid form into water in the liquid form and carbon dioxide in the gaseous form.  Therefore, it is a physical reaction.
21. By the way, the above change is different from when you “burn” sugar on stove because this is now a chemical change.
22. The unit “joule” is used only for energy, not for heat.
23. Heat capacity depends on mass, the greater the mass of an object, the greater is its heat capacity regardless of its specific heat capacity.
24. Weight and mass are the same.  Thus, your weight is about 6 times less on the moon, and so is your mass.
25. Protons in the nucleus and electrons can attract to each other, which is the cause of the decrease in atomic size from left to right on the same row of the periodic table.
26. The atomic number of element is defined as the number of electrons of the element.
27. One atomic mass unit (amu) is 1/12 of the atomic weight of a carbon-12 atom, thus is a very small value in terms of the mass unit g.
28. The light from the sun contains all colors, thus this light energy is not quantized.
29. Electrons can be filled into orbitals in any order as long as you start from the smallest principle energy level to the largest in order.
30. The neutrons in the nucleus have no charge, which makes the nucleus of atoms neutral in charge.
31. Pauli exclusion principle states that an orbital can always be occupied with 2 electrons.
32. When you work on electron configuration, you just need to know the number of electron.  You don not need to know which atom you are dealing with.
33. The electron configuration 1s² 2s¹ means that there are one of s² and two of s¹ orbitals.
34. The maximum of 37 electrons can be filled in 5f sublevels (orbitals).
35. The color of light emitted by a hot substance is characteristic of the element in the substance, such as in the case of fireworks.
36. In his periodic table, Mendeleev arranged the elements in ascending order of atomic number.
37. The outermost sublevels, such as s, p, and d orbitals, are always partially filled, unless it is an inert gas.
38. The energy of all the sublevels in the principal energy level 3 is always lower than the energy of the sublevels in the principal energy level 4.
39. The elements can be roughly grouped in 4 blocks, s, p, d, and f blocks.
40. Ionization energy is the energy required to remove an electron from an atom in the state the atom is, such as Fe and Cu in the solid state, thus is very convenient to use to determine whether or not the atom is stable in that state.
41. If sufficient energy is provided, more than one electron can be removed from any atom.
42. The first ionization energy of Na is lower than that of Mg. However, the second ionization energy of Na is much higher than that of Mg.
43. The third ionization energy of Mg is expected to be dramatically higher than its second ionization energy.
44. Upon formation of compounds, atoms tend to gain inert gas electron configuration.
45. Different elements can have the same electron configuration.
46. The electrons in noble gases cannot be removed at all.
47. Magnetic resonance imaging (MRI) is based on the concept of nuclear magnetic resonance which uses nuclear radiation to obtain the image of patients, thus should be avoided!
48. The elements present in a compound have fixed proportions (or ratios), regardless of the source (whether it is “natural vitamins” or “synthetic vitamins”).
49. The mass number of the different isotopes of oxygen are identical.
50. All the isotopes of an element are radioactive.
51. Atoms cannot be changed into other atoms at all by any reaction!
52. After about 100 half-lives, a radioisotope sample will have completely decayed and shows no radioactivity any more.
53. Metals can easily lose any number of electrons to form stable metal ions.
54. The Alpha particle is the He nucleus.
55. The beta particle is an electron which has the same energy as the electron envolved in chemical bonding.
56. The gamma ray contains neutral particles with energy higher than the alpha and the beta particles.
57. Pauli exclusion principle states that an orbital is always occupied with 2 electrons.
58. When you work on electron configuration, you just need to know the number of electron.
59. You do not need to know which atom you are dealing with.
60. Noble gases usually do not form compounds under normal conditions because their outer most (valence) orbitals are filled.
61. A methane molecule CH₄ has a square shape.
62. Different elements can have the same electron configuration.
63. The VSEPR theory states that only chemical bonds are involved in the determination of the shapes of molecules, the unshared electron pairs have nothing to do with the shapes.
64. In ionic compounds, such as NaCl and CaCl₂, the cations and anions have electron configurations of the noble gases.
65. Coordinate covalent bonds are also formed by electron sharing between atoms.
66. F can easily gain 1 electron, and O can easily gain 2 electrons to form compounds.

Part II. Multiple Choice Questions

1.  Which of the following ones is NOT a solution?
          (1) air (2) coke (3) saline (4) blood (5) alloy

2.  Absolute zero is (1) –273 K (2) –273 °F (3) –273 °C.

3.  The ceramic tiles on the space shuttle cannot be heated up easily because they have ______ heat capacity.
          (1) very high (2) very low (3) nothing to do with heat capacity!

4.  After an observation of a phenomenon, a (1) scientific law, (2) theory, (3) hypothesis, (4) proposal can be made and tested by experiments.

5.  Which of the followings is a physical change:
         (1) cooking a steak,  (2) burning oil,  (3) changing color of leaves,   (4) sugar in boiling water,   (5) none of above.

6.  Which statement is true:
         (1) An element can be easily converted to another element by simple chemical reactions.
         (2) Heat dark brown iodine solid in the absence of oxygen turns the solid into a purple gas.  This is a chemical change because of the change of color.
         (3) Passing electricity through water causes the formation of gas bubbles even though the temperature stays below the boiling point of water. This is a chemical change.
         (4) All of the above are true.

7.  Dry ice (solid CO₂) characteristically changes directly from the solid state to the gaseous state.  This physical change is called
         (1) evaporation,  (2) vaporization,  (3) gasification,  (4) sublimation, (5) all of the above.

8.  Which of the following is the highest temperature?
         (1) 450 K, (2) 450 °C, (3) 450 °F, (4) All represent the same temperature, (5) Not comparable because of their different units.

9. The boiling point of benzene is 80.0 °C.  Five measurements of the point are obtained as 82.5, 81.5, 80.1, 78.5, and 77.5 °C.  These measurements have
          (1) good accuracy good precision.  (2) good accuracy and poor precision.
          (3) poor accuracy and good precision.  (4) poor accuracy and poor precision.

10. Which one is the lowest temperature?
          (1) 100 °C  (2) 100 °F (3) 100 K (4) Not comparable!

11.  The number of the significant figures of the measurement 2.0200 x 10^-2 g is:
         (1) 3,  (2) 1,  (3) 5,  (4) 8,  (5) cannot determine.

12.  The measurement 2.0200 x 10^-2 g in decimal notation is
         (1) 2.020000 g,  (2) 202.00 g,   (3) 0.0202 g,  (4) 0.020200 g.

13.  Which of the followings is scientifically correct?
        (1) 12.4 mg + 3.54 mg + 21 mg = 36.94 mg,
        (2) 2.36 m x 8.4 m = 19.824 m²,
        (3) 3.200 m x 1.22 = 3.904 m,
        (4) all of 1-3,
        (5) none of 1-3.
 
14.  A unit of density can be
        (1) g/L,  (2) pound/L  (3) kg/gallon,   (4) all of them.

15.  How many of the following measurements have 3 significant figures, 14.03 g, 0.017 km, 5.30 x 102 mL, 6.780 mg, 0.171 L?
        (1) 1,   (2) 2,   (3) 3,   (4) 4,   (5) 5.

16.  How much heat is required to heat 225 g water from 25 °C to 100 °C?  (The specific heat capacity of water is 1 cal/g °C.)
        (1) 3.0 cal,  (2) 5.6 x 10³ cal,  (3) 1.7 x 10⁴ cal,  (4) 0.33 cal,  (5) none of above.

17.  To raise the temperature of an amount of water by 25.0 °C requires 0.85 kcal.  What is the mass of the water?
        (1) 34 kg,  (2) 34.0 kg,  (3) 34 g,  (4), 34.0 g,  (5) 34.00 g.

18.  Which of the following items does not contain heat (calories)?
        (1) skim milk,   (2) apple,  (3) carrot,  (4) non-sugar cookies,  (5) All of the above contain heat!

19.  When you mix 5.0 g of water at 20 °C with 10 g of water at 50 °C, the final temperature is
         (1) 30,  (2) 35,  (3) 40,  (4) 45 °C.  (5) cannot be determined!

20.  You were testing three materials for heat insulation.  You gave same amount of heat to all 3 materials.  You found that 1.0 g of material A  raised temperature by 10 °C, 1.5 g material B raised 20 °C, and 2.0 g material C raised 15 °C.  Which one is a better heat insulator?
        (1) A,  (2) B,  (3) C,   (4) They are the same!  (5) Cannot determine!

21. Which is a chemical change?
        (1) melting of smow,    (2) making tea from a tea bag,    (3) evaporating ocean water to obtain salt, (4) rusting of iron,     (5) all of the above.

22. How many ounces are in 2.86 kg? (1 kg = 2.205 lb and 1 lb = 16 oz)
        (1) 0.081 oz,    (2) 20.8 oz,    (3) 101 oz,    (4) 12.3 oz,    (5) none of above.

23. The density of ethanol is about 0.8 g/mL.  The mass of 20 L ethanol is
        (1) 16 g,    (2) 0.04 kg,    (3) 16 kg,    (4) 25 kg,    (5) none of above.

24. Which is not a form of energy?
        (1) electricity,    (2) heat,        (3) light,    (4) temperature,        (5) all of them ARE forms of energy.

25. How many calories are required to heat 755 g of iron from 23 °C to 175 °C if the specific heat capacity is 0.11 cal/(g °C)?
        (1) 130 cal,  (2) 1430 cal,  (3) 56 cal,  (4) 13 kcal.
** This question can be changed into several different questions by changing the mass, the temperature, or/and the material.

26. The specific heat of aluminum is 0.22 cal/(g °C).  If 300 cal heat is added to 10.0 g of Al at 25 °C, what will the final temperature of this Al be?
        (1) 208 °C,  (2) 161 °C, (3) 136 °C, (4) 55 °C, (5) none of above.
** This question can be changed into several different questions by changing the mass, the temperature, or/and the material.
** Which one is a better heat conductor, Fe or Al?

27.  When a same amount of heat is given to 1 g and 10 g of Fe at a same temperature, which one has higher final temperature?
        (1) 1 g Fe,  (2) 10 g Fe,  (3) same final temperature,  (4) Cannot compare.

28. A breakfast cereal contains 110 nutritionist's cal/oz.  How much is this in cal/g if 1 oz = 28.35 g?
        (1) 3880,  (2) 3118,  (3) 3.118, (4) 3.88 cal/g.

29. If the recommended dosage of a prescribed drug is 2 mg/kg of body weight, the amount of the drug that should be administered to a 12 lb infant is (1 lb = 0.453 kg)
        (1) 11,  (2) 4, (3) 3, (4) 22 mg.

30. The "blue ice" utilized for keeping things cool in a cooler should have ________ specific heat capacity because it can absorb a lot of heat before it needs to be replaced.
        (1) large,    (2) small,  (3) Does not matter.
** Does the blue ice "release cold" to the items in the cooler?

31. What is the maximum number of electrons that can be filled into the second principal energy level of an atom?
          (1) 4  (2) 6  (3) 8  (4) 10  (5) 18

32. What is the maximum number of electrons that can be filled into the third principal energy level of an atom?
          (1) 4  (2) 6  (3) 8  (4) 10  (5) 18

33. The maximum number of electrons and number of orbitals, respectively, in the 4d energy sublevel are
         (1) 6 and 3.  (2) 10 and 5.  (3) 2 and 1.  (4) 4 and 2. (5) 18 and 9.

34. Isotopes of an element
        (1) contain the same number of neutrons. (2) have different nuclear charges. (3) must have the same atomic number. (4) must have the same mass.

35. The number 60 in cobalt-60 represents
         (1) the atomic number. (2) the mass number. (3) the number of the protons. (4) the sum of the protons and electrons. (5) the number of the neutrons.

36.  The first ionization energy of sodium is 118.5 kcal/mol.  The second ionization energy compared with the first ionization energy is most probably
         (1) about the same. (2) about double. (3) much lower. (4) much higher.

37.  An orbital is best described as
          (1) an electron's path.  (2) a probability region of finding electrons  (3) an energy level.  (4) an energy sublevel.

38.  The nucleus of an atom is
          (1) positively charged and has a high density.
          (2) positively charged and has a low density.
          (3) negatively charged and has a high density.
          (4) negatively charged and has a low density.

39. We would expect the electron configuration of oxygen to show ______ (how many?) unpaired electrons in its p orbitals according to the Hund's rule.
          (1) zero (2) one  (3) two  (4) three

40. Which one has the electron configuration 1s² 2s² 2p⁶?
          (1) Na⁺ (2) Mg²⁺ (3) Ne  (4) F^–  (5) All of them!
        What is the number of electrons for each of the above atom/ion?

41. Which element has the smallest first ionization energy?
          (1) P (2) Si  (3) Al  (4) Mg  (5) Na

42. Which element has the lowest third ionization energy?
          (1) P (2) Si  (3) Al  (4) Mg  (5) Na

43. Which element has the largest atomic radius?
          (1) F (2) Cl  (3) Br  (4) I   (5) At
**For more "Which element" questions, please refer to the book!
For example:
The element ___ is widely used in the manufacture of electronic chips.  (P. 99)
The element ___ can be found in DNA, bones, and teeth.  The element itself is very sensitive to oxygen.  (P. 99)
The element ___ is toxic when it is taken into the body at certain level, but is an essential trace element for our health which can lower the risk of heart attack. (P. 101)
The metal ___ is found in vitamin B₁₂.  (P. 103)

44. When Mg reacts with oxygen gas, you expect the formation of
          (1) MgO  (2) MgO₂ (3) Mg₂O (4) Mg₂O₃

45. A metal that is an ingredient of the alloy used as implant material:
          (1) Ag (2) Cu  (3) Au  (4) Ti  (5) Hg

46. The element in hemoglobin that is responsible of oxygen binding is
          (1) Fe (2) Cu  (3) Ni  (4) Zn  (5) Co
**For more "what metal is in what protein/enzyme" questions, please refer to the lecture notes.

47. We would expect the electron configuration of nitrogen to show ______ (how many?) unpaired electrons in its p orbitals according to the Hund's rule.
          (1) zero  (2) one   (3) two   (4) three  (5) four

48. Which one has the electron configuration 1s2 2s2 2p6?
         (1) Na⁺  (2) Mg²⁺  (3) Ne   (4) F^–    (5) All of them!
**More electronconfiguration questions:
Write the electron configuration of the followings:
(Count the number of electrons for each atom or ion!  Please refer to the lecture note for these examples.)
         (a) Na; (b) Na⁺; (c) O^2–;  (d) Fe²⁺

49. Which element has the lowest third ionization energy?
         (1) P   (2) Si    (3) Al    (4) Mg   (5) Na

50. A metal that is an ingredient of the alloy used as implant material:
         (1) Ag   (2) Cu   (3) Au   (4) Ti    (5) Hg

51. Which element has the smallest second ionization energy? (How about the first and third IE?)
         (1) P   (2) Si    (3) Al    (4) Mg   (5) Na

52. Isotopes of an element
         (1) contain the same number of neutrons.    (2) have different nuclear charges.
         (3) must have the same atomic number.    (4) must have the same mass.

53. The number 60 in cobalt-60 represents
 (1) the atomic number.   (2) the mass number.    (3) the number of the protons.
 (4) the sum of the protons and electrons.     (5) the number of the neutrons.

54. The number of neutron in ¹⁴₆C is
 (1) 14,   (2) 6,   (3) 7,   (4) 8  (5) 20.

55. The number of neutron in hydrogen atom ¹₁H is
  (1) 1,   (2) 2,   (3) 3,   (4) 0,   (5) Cannot be determined!

56. The most abundant element in terms of number of atoms in our body is
 (1) carbon (2) water (3) sodium (4) hydrogen  (5) oxygen

57. If an isotope undergoes beta-particle emission,
 (1) the mass number changes.
 (2) the atomic number changes.
 (3) the number of neutrons remains the same.
 (4) the number of electrons remains the same.
 (5) the number of protons remains the same.

58. What is the atom generated after an alpha particle is emitted from ²³⁸₉₂ U?
 (1) ²³⁷₉₂ U  (2)²³⁴₉₂ U  (3) ²³⁷₉₀ Th  (4) ²³⁴₉₀ Th

59. How much does 100 g I-131 remain after 100 days?  I-131 has t1/2 = 8 days.
 (1) 1 g  (2) 8 g  (3) 0.0173 g (4) 12.5 g

60. C-14 decays to produce N-14.  What is emitted?
 (1) alpha particle (2) beta particle  (3) hydrogen atom (4) gamma ray

61. Upon radiation, _______ is eventually generated which can cause damages of proteins and nucleic acids.
 (1) alpha particle (2) beta particle  (3) hydrogen atom (4) hydroxyl radical

62. The unit that is used for the rate of radiation decay, i.e., a measure of the number of atoms that decay per second.
 (1) rad  (2) rem  (3) curie (Ci)  (4) roentgen (R)
**What are the definitions for the other units?

63. ²³⁸₉₂U decays all the way to the stable ²⁰⁶₈₂Pb.  How many alpha decays are associated with this nuclear reaction?
 (1) 4  (2) 8  (3) 32  (4) Cannot be determined!

64. The electron dot structure for the hydroxide ion OH^– is____________.

65. Which one has the electron configuration 1s² 2s² 2p⁶?
 (1) Na⁺  (2) Mg²⁺  (3) Ne    (4) F^–    (5) All of them!

66. The IIIA group of elements have ______ valence electrons.
 (1) 1  (2) 2  (3) 3  (4) 4  (5) 5

67. The radioactive gas ²²²₈₆Rn decays to form ²¹⁸₈₄Po, and emits _____.
 (1) an alpha particle.  (2) a beta particle. (3) a positron.

68. After how many half-lives can a radioactive isotope of 64 g decay to only 2 g?
 (1) 1  (2) 2  (3) 3  (4) 4  (5) 5

69. The most penetrating radiation is
 (1) a radiation (2) b radiation  (3) g radiation  (4) X-ray radiation

70. Which compound is not an ionic compound?
 (1) NaCl (2) CaCl₂ (3) LiO  (4) CCl₄ (5) Ca(CO₃), calcium carbonate