3.The atomic mass of rhenium is 186.2. Given that 37.1% of natural rhenium is rhenuim-185,what is the other stable isotope?
(A)
(B)
(C)
(D)
(E)

複選題9.下列哪兩項是熱帶海域水面多呈藍色的原因? (A)海面反射天空的藍色光波 (B)海水對藍光的消光作用最弱 (C)太陽光只有藍色的光波到達海面 (D)海水中的鹽類會釋出藍色的光波 (E)相於藍光,其他可見光可穿透至更深的水層

複選題10.圖六是海洋研究船在某處海域取得甲、乙、丙、丁四測點的深海岩心地磁紀錄,其中黑色表示和現在磁極方向相同,白色表示和現在磁極方向相反。從各測點岩心標本的比較與分析,下列哪些推論正確? (A)第三紀結束時地磁是反轉的 (B)四測點中,丙測點取得最老的地質年代岩心(C)最後百萬年的平均沉積速率,乙測點是最慢的 (D)甲測點的沉積作用曾變慢後,再變快 (E)乙測點離中洋脊最近

1. Which of the following pairs is incorrect? (A)NH4Br, ammo onium bromide (B)K2,CO3,potassium carbonate (C)BaPO4 , barium phosphate (D) CuCl,copper(I) chloride (E) MnO2, manganese (IV) oxide

2. Rutherford's experiment was important because it showed that: (A)radioactive elements give off alpha particles. (B)gold foil can be made to be only a few atoms thick. (C) a zinc sulfide screen scintillates when struck by a charged particle. (D) the mass of the atom is uniformly distributed throughout the atom. (E) an atom is mostly empty space.

4. The following reactions are examples of (A)precipitation reactions. (B)redox, precipitation, and acid-base, respectively. (C)precipitation (two) and acid-base reactions, respectively. (D) redox reactions. (E) none ofthese 75 Re , D) 7s Re

5. A 0.307-g sample of an unknown triprotic acid is titrated to the third equivalence point using 35.2 mL of 0.106 M NaOH. Calculate the molar mass of the acid. (A)247 g/mol (B)171g/mol (C)165 g/mol (D) 151 gmol (E) 82.7gmol

6. Consider two organic molecules, ethanol and benzene. One dissolves in water and the other does not. Why? (A)They have different molar masses. (B)One is ionic, the other is not. (C)One is an electrolyte, the other is not. (D) Ethanol contains a polar O–H bond, and benzene does not. (E) Two ofthese.

7. Calculate the density of nitrogen at STP. (A)0.312 g/L (B)0.625 g/L (C)0.800 g/L (D) 1.25 g/L (E) 1.60 g/L

8. The van der Waals equation, , incorporates corrections to the ideal gas law in order to account for the properties of real gases. One of the corrections accounts for (A) the possibility of chemical reaction between molecules. (B) the finite volume of molecules. (C)the quantum behavior of molecules. (D) the fact that average kinetic energy is inversely proportional to temperature. (E) the possibility of phase changes when the temperature is decreased or the pressure is increased.

9. A 25.0 g piece of aluminum (which has a molar heat capacity of 24.03J/℃mol) is heated to 82.4*C and dropped into a calorimeter containing water (specific heat capacity of water is 4.18J/g℃initially at 22.3C. The final temperature of the water is 24.9℃. Calculate the mass of water in the calorimeter. (A)118 g(B)6.57g (C)3180g (D) 2120g (E) none of these