How many electrons must be accounted for in the Lewis dot structure for the carbonate ion?Choose one answer.a. 20 b. 22 c. 23 d. 24Using bond dissociation energy approximate the enthalpy change for the combustion reaction of 2 moles octane (C8H18 ) and 25 moles oxygen (O2 ) to form carbon dioxide (CO2 ) and water (H2O).C–C bonds (346 kJ)C–H bonds (413 kJ)O–O bonds (498 kJ)C–O bonds (732 kJ)O–H bonds (463 kJ)Which of the following has bond angles of 109.5°?Choose one answer.a. SeCl4 b. XeF4 c. SiF4 d. SF4The bonding in BF3 requires formation of hybrid orbitals on boron. If the molecule is oriented in the xy plane what is the identity of the unfilled p orbital on boron?Choose one answer.a. 2s b. 2px c. 2py d. 2pzWhich of the following statement is true regarding the paramagnetic property of O2 molecule and the diamagnetic property of N2?Choose one answer.a. The electronic configuration using the molecular orbital theory shows that N2 contains 2 unpaired electrons while O2 contains no unpaired electrons. b. The electronic configuration using the molecular orbital theory shows that O2 contains 2 unpaired electrons while N2 contains no unpaired electrons. c. The electronic configuration using the molecular orbital theory shows that O2 contains 1 unpaired electrons while N2 contains no unpaired electrons. d. Both Valence Bond theory and molecular orbital theory can not explain why O2 is paramagnetic and N2 is diamagnetic.Which of the following cannot absorb a visible photon?Choose one answer.a. He b. He2 c. He d. All of these species can absorb visible light.Determine the wavelength for electromagnetic radiation having a frequency of 5.55 × 1015 s-1.Choose one answer.a. 1.85 × 107 m b. 1.19 × 10-49 m c. 5.40 × 10-8 m d. 5.40 × 108 mWhich of the following would provide the greatest resolution in order to observe a virus?Choose one answer.a. electromagnetic radiation with a frequency of 7.3 × 1018 s-1 b. electromagnetic radiation with a frequency of 8.9 × 1015 s-1 c. electromagnetic radiation with a wavelength of 3.5 × 10-10 m d. electromagnetic radiation with a wavelength of 2.1 × 10-9 mWhen is an electron said to have zero potential energy?Choose one answer.a. When it is in the lowest energy level. b. When it is in the 1s orbital. c. When it is infinitely separated from the nucleus. d. When it is in the largest orbital.Which of the following listed in n l ml ms order is not an acceptable set of quantum numbers?Choose one answer.a. 2 0 0 -1/2 b. 2 3 1 1/2 c. 3 2 0 1/2 d. 3 2 0 -1/2What is the energy per photon of the lowest frequency of electromagnetic radiation that can be used to observe a gold atom with a diameter of 280 picometers? (1 picometer = 1 × 10-12 meter)Choose one answer.a. 1.1 × 1018 J b. 5.6 × 10-11 J c. 7.1 × 10-16 J d. 6.2 × 10-52 JUnder what circumstances does the Bohr model fail to make accurate predictions of an atom’s spectra?Choose one answer.a. When the atom absorbs light rather than emitting it b. When the mass number of the atom is greater than 1 c. When the quantum number of an electron is 3 or greater d. When the number of electrons in the atom is greater than 1 Why are X-rays rather than visible light used in airport security systems that scan luggage?Choose one answer.a. X-rays can detect drugs. b. X-rays can penetrate the outside of the suitcase to “see” what is inside. c. X-rays can detect explosives. d. Visible light is too sensitive to be used.The Stern-Gerlach experiment showing two different electron spins was first carried out using silver atoms (?[Kr]?4d105s1?). The experiment will work with other elements but only certain ones. Which of the following elements would demonstrate the effect seen in the Stern-Gerlach experiment?Choose one answer.a. cadmium b. potassium c. magnesium d. xenon An atom of helium has a de Broglie wavelength of 4.3 × 10-12 meter. What is its velocity?Choose one answer.a. 1.5 × 10-23 m?/?s b. 2.3 × 104 m?/?s c. 3.0 × 108 m?/?s d. 4.3 × 10-19 m?/?s The x- y- and z-coordinates of a point are (1 0 0). What are the values of ? and f for this point using spherical coordinates? (Assume that ? is the angle between the point and the z-axis and that f is the angle between the x-axis and a projection of the point onto the xy-plane.)Choose one answer.a. ? = 0°; f = 0° b. ? = 0°; f = 90° c. ? = 90°; f = 0° d. ? = 90°; f = 90°A point has spherical coordinates (r ? f) of (5 90° 90°). What are the rectangular coordinates (x y z) of this point? (Assume that ? is the angle between the point and the z-axis and that f is the angle between the x-axis and a projection of the point onto the xy-plane.)Choose one answer.a. (5 0 0) b. (0 5 0) c. (0 0 5) d. (5 5 0)What would a 2py orbital look like if the angular part of its wave function were constant?Choose one answer.a. Its shape would be similar to that of a 1s orbital. b. It would be a single point positioned at the nucleus. c. It would resemble two spheres one on either side of the xz-plane. d. It would resemble a 2s orbital except that it would have a node in the xz-plane.How many unique distinct values of ml 3d orbitals are there and how many angular nodes do they have?Choose one answer.a. 4 and 3 b. 5 and 3 c. 4 and 2 d. 5 and 2
