Physics Exam: Electromagnetism and Atomic Structure, Study notes of Chemistry

Download Physics Exam: Electromagnetism and Atomic Structure and more Study notes Chemistry in PDF only on Docsity! 1031_3rd Exam_1031217 MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) The distance between adjacent crests in an electromagnetic wave is called A) amplitude B) frequency C) area D) median E) wavelength Answer: E 2) Which of the following colors of electromagnetic radiation has the shortest wavelength? A) blue B) yellow C) green D) violet E) orange Answer: D 3) Which kind of electromagnetic radiation contains the greatest energy per photon A) infrared radiation B) X-rays C) microwaves D) visible light E) gamma rays Answer: E 4) Calculate the energy of the red light emitted by a neon atom with a wavelength of 703.2 nm. (Planck’s Constant h = 6.626 × 10 34 J · s) A) 2.83 × 10-19 J B) 4.27 × 10-19 J C) 6.45 × 10-19 J D) 3.54 × 10-19 J E) 2.34 × 10-19 J Answer: A 5) A nitrogen gas laser pulse with a wavelength of 337 nm contains 3.83 mJ of energy. How many photons does it contain? A) 3.83 × 109 B) 5.90 × 103 C) 7.44 × 1012 D) 9.25 × 1018 E) 6.49 × 1015 Answer: E 6) Which of the following statements is TRUE? A) An orbital is the volume in which we are most likely to find an electron. B) The emission spectrum of a particular element is always the same and can be used to identify the element. C) Part of the Bohr model proposed that electrons in the hydrogen atom are located in "stationary states" or particular orbits around the nucleus. D) The uncertainty principle states that we can never know both the exact location and speed of an electron. E) All of the above are true. Answer: E A_1 7) Calculate the wavelength of a baseball (m = 155 g) moving at 32.5 m/s. (1 J = 1 kg · m2/s2) A) 2.68 × 10-34 m B) 1.32 × 10-34 m C) 3.57 × 10-32 m D) 7.60 × 10-36 m E) 2.15 × 10-32 m Answer: B 8) It is possible to determine the ionization energy for hydrogen using the Bohr equation. Calculate the ionization energy (in kJ) for a mole of hydrogen atoms, making the assumption that ionization is the transition from n = 1 to n = . (Rydberg constant RH = 2.18 x 10-18 J) A) 3.62 × 103 kJ B) 5.33 × 103 kJ C) 1.31 × 103 kJ D) 2.76 × 103 kJ E) 7.62 × 103 kJ Answer: C 9) Which of the following statements is TRUE? A) An orbital is the path that an electron follows during its movement in an atom. B) The magnetic quantum number (ml) describes the orientation of the orbital. C) The principal quantum number (n) describes the shape of an orbital. D) The angular momentum quantum number (l) describes the the size and energy associated with an orbital. E) All of the above are true. Answer: B 10) What value of l is represented by a d orbital? A) 0 B) 2 C) 3 D) 1 Answer: B 11) Give the numbers for ml for a d orbital. A) -1, 0, 1 B) 0, 1, 2 C) 1, 2, 3 D) -2, -1, 0, 1, 2 Answer: D 12) Describe the shape of a s orbital. A) dumbbell shaped B) spherical C) eight balls D) four balls E) three balls Answer: B A_2 24) Which reaction below represents the second ionization of Sr? A) Sr (g) Sr2 (g) + e B) Sr (g) + e Sr(g) C) Sr(g) Sr (g) + e D) Sr2 (g) + e Sr (g) E) Sr (g) + e Sr2 (g) Answer: A 25) Place the following in order of increasing atomic radius. As O Br A) O < Br < As B) O < As < Br C) As < O < Br D) Br < As < O E) As < Br < O Answer: A 26) Place the following in order of decreasing radius. Te2 F O2 A) F > O2 > Te2 B) Te2 > O2 > F C) Te2 > F > O2 D) F > Te2 > O2 E) O2 > F > Te2 Answer: B 27) For which element would the atoms be expected to be diamagnetic? A) Na B) Sr C) Ge D) Co E) H Answer: B 28) Which of the following species would have the greatest attraction to a magnetic field? A) O2- B) Fe3+ C) Fe2+ D) Fe-2 E) Fe Answer: B 29) The similar chemical behavior of the elements in a given group in the periodic table is best accounted for by the fact that atoms of these elements have: A) the same number of electrons in the outermost (valence) shell B) the same number of protons C) the same number of electrons D) the same number of isotopes E) similar nuclear structures Answer: A A_5 30) Identify a characteristic of halogens. A) powerful reducing agents B) absorbs water in reactions C) powerful oxidizing agents D) forms water in reactions E) inert Answer: C 31) Which of the following represent the Lewis structure for Ca2 ? A) B) C) D) E) Answer: E 32) Which is the correct Lewis structure for magnesium bromide? A) B) C) D) E) Answer: C 33) Which of the following reactions is associated with the lattice energy of CaS ( H°latt)? A) CaS(s) Ca2 (aq) + S2 (aq) B) Ca2 (aq) + S2 (aq) CaS(s) C) CaS(s) Ca(s) + S(s) D) Ca2 (g) + S2 (g) CaS(s) E) Ca(s) + S(s) CaS(s) Answer: D 34) Place the following in order of decreasing magnitude of lattice energy. K2O Rb2S Li2O A) Li2O > Rb2S > K2O B) Li2O > K2O > Rb2S C) Rb2S > K2O > Li2O D) K2O > Li2O > Rb2S E) Rb2S > Li2O > K2O Answer: B A_6 35) Use the data given below to construct a Born-Haber cycle to determine the bond energy of O2. ∆H°(kJ) Na(s) Na(g) 107 Na(g) Na (g) + e 496 O(g) + e O (g) -141 O (g) + e O2 (g) 878 2 Na(s) + 1 2 O2(g) Na2O(s) -416 2 Na (g) + O2 (g) Na2O(s) -2608 A) 852 kJ B) 356 kJ C) 249 kJ D) 426 kJ E) 498 kJ Answer: E 36) A triple covalent bond contains ________ of electrons. A) 3 pairs B) 4 pairs C) 0 pairs D) 2 pairs E) 1 pair Answer: A 37) Identify the number of bonding pairs and lone pairs of electrons in water. A) 2 bonding pairs and 2 lone pairs B) 2 bonding pairs and 1 lone pair C) 3 bonding pairs and 2 lone pairs D) 1 bonding pair and 2 lone pairs E) 1 bonding pair and 1 lone pair Answer: A 38) Which of the following has the most negative electron affinity: Li, Be, N, O, F? A) F B) N C) O D) Li E) Be Answer: A 39) Choose the bond below that is most polar. A) H-I B) C-H C) H-Cl D) H-Br E) H-F Answer: E 40) Place the following in order of decreasing XO bond length, where "X" represents the central atom in each of the following compounds or ions. SiO32 CO2 CO32 A) CO32 > SiO32 > CO2 B) SiO32 > CO32 > CO2 C) CO2 > CO32 > SiO32 D) CO32 > CO2 > SiO32 E) CO2 > SiO32 > CO32 Answer: B A_7 46) Use formal charge to choose the best Lewis structure for CH3SOCH3. A) B) C) D) E) Answer: A 47) Which of the following processes are exothermic? A) Li(s) Li(g) B) Br(g) + e Br (g) C) Cl2(g) 2Cl(g) D) NaF(s) Na (g) + F (g) E) None of the above are exothermic. Answer: B 48) Use the bond energies provided to estimate H°rxn for the reaction below. C2H4(g) + H2(g) C2H6(g) H°rxn = ? Bond Bond Energy (kJ/mol) C-C 347 C-H 414 C=C 611 C C 837 H-H 436 A) +98 kJ B) -102 kJ C) -166 kJ D) -128 kJ E) +700 kJ Answer: D A_10 49) Which compound would be expected to have the shortest nitrogen-nitrogen bond? A) N2 B) H2NNH2 C) (CH3)2NNH2 D) HNNH E) O2NNO2 Answer: A 50) Why is the electron affinity so positive for the group 2 elements? A) The groups 2 elements are diatomic elements. B) The added electron would have to be added into the half-filled p subshell. C) The added electron would have to go into a new shell. D) Electrons can't be added to gases. E) The added electron would have to be added into the p subshell. Answer: E A_11