20.Rank the following species in order of increasing polarity of the carbon-metal bond (lest®most polar):
(A)C < A < B
(B)B < A < C
(C)A < C < B
(D)B < C < A
(E)A < B < C 

16.The following problem refers to the 1H nmr spectrum of CH3CH2OCH2OCH2CH3. (A)12 (B)5 (C)4 (D)3 (E)6

17.The relationship between magnetic field strength and the energy difference between nuclear spin states is: (A)The are independent of each other. (B)They are directly proportional. (C)They are inversely proportional. (D)They relationship varies from molecule to molecule. (E)None of these.

18.An infrared spectrum exhibits a broad band in the 3000 to 3500cm-1 region and a strong peak at 1710cm-1 . Which of the following substances best fits the data?  (A)C6H5CH2CH2OH (B)C6H5CH2COOH (C) (D) (E)

19.Which (if any) of the following would not be classified as an organometallic substance? (A)Triethylaluminum (B)Ethylmagnesium iodide (C)Potassium tert-butoxide (D)None of these(all are organometallic compounds) (E)All of these.

21.How many electrons in an atom can have of the following quantum number or sublevel designations? (choosing the correct answers) (I) n = 2，I = 1. (II) 3d. (III) 4s. (IV) 4p. (V) n = 3. I = 1，m1 = 1. (VI) n=5, I=3. (A)(I) + (II) = 15e- (B)(III) + (IV) = 8e- (C)(V) + (VI) = 15e- (D)(I) + (II) + (V) = 10e- (E)(II) + (IV) + (VI) = 28e-

22.Of the following sets of four quantum numbers, identify the ones that can exist for an electron in an atom? (A) n = 1，I = 1，m1 = 0，ms = 1/2. (B) n = 2，I = 0，m1 = ±1，ms = 1/2. (C) n = 3，I = 3，m1 = ±3，ms = -1/2. (D) n = 4，I = 3，m1 = ±2，ms = 1/2. (E) n = 4，I = 4，m1 = -1，ms = 1/2.

【已刪除】複選題23.How many valence electrons in an element can have for each of the following species? (choosing the correct answers) (I)P3+ (II)Rh2+ (III)Co4+ (IV)Mn3+ (V)Ni2+ (VI)Si2+ (VII)Sb (VIII)B1+ (AB)(I) + (III) = 8e- (AC)(II) + (VI) = 8e- (AD)(III) + (VII) = 9e- (AE)(I) + (IV) + (VIII) = 6e- (BC)(II) + (V) + (VII) = 18e-(BD)無答案

24.Which of the following statements is not correct? (A)According to the VSEPR theory, the I3- molecule is predicted to be linear. (B)According to the VSEPR theory, the InF4 1- molecule is predicted to be tetrahedral. (C)According to the VSEPR theory, the GeBr 3 1- molecule is predicted to be trigonal planar (D)According to the VSEPR theory, the C1I3 molecule is predicted to be T-shaped. (E)According to the VSEPR theory,TeS3 2- molecule is predicted to be pyramidal.

25. Suppose the hypothetical set of quantum numbers:n = 1, 2, 3, ……l = 0, 1, 2, 3, …… , n–1mₗ = 1s = 1/2, –1/2then which of the following statements is not correct?(A) There is one s orbital, one p orbital, and one d orbital.(B) The atomic number of the first element in the d orbital-filler is 12.(C) There are two transition elements in the first period.(D) The atomic number of the first inert gas is 2.(E) If one element has the atomic number 14, then its electron configuration is 1s²2s²2p³3s²3p².

26.Arrange in decreasing order of stability of the following four isomers. (I)cis-1-chloro-2-methylcyclohexane (II)trans-1-chloro-2-methylcyclohexane (III)cis-1-chloro-3-methylcyclohexane (IV)trans-1-chloro-3-methylcyclohexane (A)(II) > (III) > (I) > (IV) (B)(I) > (II) > (IV) > (III) (C)(III) > (II) > (IV) > (I) (D)(IV) > (II) > (I) > (III) (E)none of the above.