ATOMIC THEORY, PERIODICITY, and NUCLEAR CHEMISTRY Note: For all questions referring to solutions, assume that the solvent is water unless otherwise stated. 1. The nuclide is radioactive and decays by the loss of one beta ( ) particle. The product nuclide is 2. The symbol of the element whose nucleus contains 27 neutrons and 22 protons is 3. Correct statements about alpha particles include which of the following? I. They have a mass number of 4 and a charge of +2. II. They are more penetrating than beta particles. III. They are helium nuclei. (A) I only (B) III only (C) I and II I and III II and III 4. Which of the following sets of quantum numbers (n, l, m l, m s ) best describes the valence electron of highest energy in a ground state gallium atom (atomic number 31)? (A) 4, 0, 0, ½ (B) 4, 0, 1, ½ (C) 4, 1, 1, ½ 4, 1, 2, ½ 4, 2, 0, ½ 5. What is the missing product in the nuclear reaction represented above? 6. For the types of radiation given, which of the following is the correct order of increasing ability to penetrate a piece of lead? (A) Alpha particles < gamma rays < beta particles (B) Alpha particles < beta particles < gamma rays (C) Beta particles < alpha particles < gamma rays Gamma rays < beta particles < alpha particles Gamma rays < alpha particles < beta particles 7. When decays, the emission consists consecutively of an particle, then two particles, and finally another particle. The resulting stable nucleus is 8. Which of the following represents a pair of isotopes? Atomic Mass Number Number (A) I. 6 14 II. 7 14 (B) I. 6 7 II. 14 14 (C) I. 6 14 II. 14 28 I. 7 13 II. 7 14 I. 8 10 II. 16 20 9. Which of the following most clearly supports the conclusion that electrons in atoms have quantized energies? (A) the emission spectrum of hydrogen (B) the photoelectric effect (C) scattering of α particles by a metal foil electron or light diffraction cathode rays 10. What type of radiation is emitted during a nuclear process in which a nucleus with a greater atomic number is formed? (A) alpha particles (B) beta particles (C) positrons gamma rays neutrons
11. When an aluminum atom is bombarded with - particles, phosphorus may be formed according to the following equation: In this process the particle X is a: (A) -particle (B) hydrogen atom (C) -ray proton neutron 12. All of the following statements concerning the characteristics of the halogens are true EXCEPT: (A) The first ionization energies (potentials) decrease as the atomic numbers of the halogens increase. (B) Fluorine is the best oxidizing agent. (C) Fluorine atoms have the smallest radii. Iodine reacts with bromide to form iodide and bromine. Fluorine is the most electronegative halogen 13. Which of the following represents the ground state electron configuration for the Mn 3+ ion? (Atomic number for Mn = 25) (A) l s 2 2s 2 2p 6 3s 2 3p 6 3d 4 (B) 1s 2 2s 2 2p 6 3s 2 3p 6 3d 5 4s 2 (C) 1s 2 2s 2 2p 6 3s 2 3p 6 3d 2 4s 2 1s 2 2s 2 2p 6 3s 2 3p 6 3d 8 4s 2 1s 2 2s 2 2p 6 3s 2 3p 6 3d 3 4s 1 14. Which one of the following solids dissolves in water to form a colorless solution? (A) CrCl 3 (B) FeCl 3 (C) CoCl 2 CuCl 2 ZnCl 2 15. How many unpaired d electrons does iron have in its ground state? (A) 2 (B) 3 (C) 4 5 6 16. How many unpaired electrons does Co +2 have in its ground state? (A) 1 (B) 2 (C) 3 4 5 17. Which of the following conclusions can be drawn from J. J. Thomson s cathode ray experiments? (A) Atoms contain electrons. (B) Practically all the mass of an atom is contained in its nucleus. (C) Atoms contain protons, neutrons, and electrons. Atoms have a positively charged nucleus surrounded by an electron cloud. No two electrons in one atom can have the same four quantum numbers. 18. One of the outermost electrons in a strontium atom in the ground state can be described by which of the following sets of four quantum numbers? (A) 5, 2, 0, 1 / 2 (B) 5, 1, 1, 1 / 2 (C) 5, 1, 0, ½ 5, 0, 1, 1 / 2 5, 0, 0, 1 / 2 19. Of the following types of radiation, how many have wavelengths longer than that of blue light? yellow light, radio waves, x-rays, violet light, infra-red light, -rays (A) 1 (B) 2 (C) 3 4 5 Questions 20 33 (A) Heisenberg uncertainty principle (B) Pauli exclusion principle (C) Hund s rule Shielding effect Wave nature of matter 20. Can be used to predict that a gaseous carbon atom in its ground state is paramagnetic C 21. Explains the experimental phenomenon of electron diffraction E 22. Indicates that an atomic orbital can hold no more than two electrons B 23. Predicts that it is impossible to determine simultaneously the exact position and the exact velocity of an electron. A
24. Einstein s explanation of the photoelectric effect was evidence for: (A) the existence of photons (B) the existence of discrete energy levels (C) the existence of orbitals the Bohr model of the hydrogen atom the wave nature of the electron 25. An electron can move from one orbital to another in a hydrogen atom. In which movement will the photon of the highest energy be emitted? (A) 2p 1s (B) 1s 2p (C) 3s 2s 2s 3s 3p 2s 26. Which of the following is not correct? (A) EN increases as you go down a group. (B) Atoms with low EN give up electrons easily (C) Atoms with high EN typically have high ionizations energies and electron affinities EN is the electron-pulling power of an atom A large EN difference between two atoms leads to a bond which is considered ionic. Questions 27-29 (A) O (B) Ga (C) Rb Ca N 27. Which of these elements has the second lowest ionization energy? D 28. Which is the most electronegative element? A 29. Which of these elements has the smallest ionic radius for its most commonly found ion? A Questions 30-33 (A) 1s 2 2s 2 2p 5 3s 2 3p 5 (B) 1s 2 2s 2 2p 6 3s 2 3p 6 (C) 1s 2 2s 2 2p 6 2d 10 3s 2 3p 6 1s 2 2s 2 2p 6 3s 2 3p 6 3d 5 1s 2 2s 2 2p 6 3s 2 3p 6 3d 3 4s 2 30. An impossible electronic configuration C 31. The ground state configuration for the atoms of a transition element E 32. The ground state configuration of a negative ion of a halogen B 33. The ground state configuration of a common ion of an alkaline earth element B 34. Which has the largest ionization energy? (A) He (B) Ne (C) Ar Cl O -2 35. The total number of electrons which can be accommodated in the n = 5 shell is: (A) 2 (B) 8 (C) 18 32 50 36. 1s 2 2s 2 2p 6 3s 2 3p 3 Atoms of an element, X, have the electronic configuration shown above. The compound most likely formed with magnesium, Mg, is (A) MgX (B) Mg 2 X (C) MgX 2 MgX 3 Mg 3 X 2 37. How many of these ions is/are paramagnetic? Ti +2, Ti +4, Mn +2, Sn +4, Ga +3, Co +2, Zn +2 (A) 1 (B) 2 (C) 3 4 5 38. Which of the following elements most readily show the photoelectric effect? (A) Noble gases (B) Alkali metals (C) Halogens Transition metals Lanthanides 39. Which of the following is not determined by the principal quantum number, n, of the electron in a hydrogen atom? (A) the energy of the electron (B) the minimum frequency of light needed to remove an electron from the atom. (C) the size of the corresponding atomic orbital(s) the shape of the corresponding atomic orbital(s) all of the above are determined by n Questions 40-42 (A) F (B) S (C) Mg Ar Mn 40. Forms monatomic ions with a 2 charge in solution B 41. One of the alkaline earths C 42. Forms oxides that give acidic solutions in water B 43. Which one of the following ions is expected to be colored? (A) Zn +2 (B) Al +3 (C) Ti +4 V +2 Cd +2
44. A possible set of four quantum numbers (n, l, m l, m s ) for an electron in a d orbital is: (A) (5,2,-1,½) (B) (4,2,0,1) (C) (5,3,-1,-½) (2,2,1,-½) (2,1,0,½) Questions 45-48 (A) Emission spectrum of hydrogen (B) The photoelectric effect (C) Alpha scattering by metal foil The occurrence of diffraction patterns The observation of cathode rays. 45. Shows that electrons have wave properties. D 46. Shows that atoms contain electrons. E 47. Shows that electrons in atoms have quantized energies. A 48. Shows the light is quantized and not continuous. B 49. The Heisenberg Uncertainty Principle says that the product of the uncertainties in two quantities is greater than Planck s Constant. What are these two quantities? (A) Position and energy (B) Position and velocity (C) Position and momentum Energy and velocity Energy and momentum 50. An orbital is best described as: (A) the path the electron takes in circling the nucleus (B) the probability distribution of the electron s location (C) the means of calculating the electron s location at a given moment the energy associated with an electron a particular wavelength of the electromagnetic spectrum 51. Which of the following has the smallest radius? (A) Cl - (B) K + (C) Cr Al +3 Ar 52. In a single atom how many electrons can have both n = 4 and m l = 2? (A) 0 (B) 2 (C) 4 8 16 53. Which of the following is predicted by the quantum mechanical model of the hydrogen atom but not by the Bohr model? (A) The emission spectrum of hydrogen is composed of lines. (B) The electron of the hydrogen atom does not fall into the nucleus. (C) The electron is further from the nucleus in states with a higher value of n. No two electrons in the same atom can have the same set of quantum numbers. An electron with a higher value of n has a higher energy. 54. Which of the following states about the photoelectric effect is correct? (A) Classical mechanics predicts that light cannot (B) Quantum mechanics predicts that light with a frequency less than a certain value cannot (C) Classical mechanics predicts that light with a frequency less than a certain value cannot eject an electron from a surface. Quantum mechanics predicts that light cannot Classical mechanics predicts that light with a wavelength less than a certain value cannot (F) Quantum mechanics predicts that light with a wavelength less than a certain value cannot 55. Which one of the following is characterized by the m l quantum number? (A) orientation of orbital in space (B) orbital energy (C) spin of electron electron velocity orbital size 56. Which of the following has the largest second ionization energy? (A) S (B) Cl (C) Ar K Ca
Questions 57 59 (A) Aufbau principle (B) Pauli exclusion principle (C) Hund s rule Shielding effect Wave nature of matter 57. States that electrons fill the lowest-energy orbitals before filling those with higher energy. A 58. Says that the lowest energy state of an atom is the one in which the greatest number of electrons in a subshell have aligned their spins. C 59. Explains the fact that in a multi-electron atom the 3p subshell is higher in energy than the 3s. D 60. How many f electrons have the value n = 3? (A) 0 (B) 2 (C) 6 10 14 61. How many electrons can be described by the quantum numbers n = 3 and m l = +1? (A) 0 (B) 1 (C) 2 3 4 (F) 8 62. Which is the correct order of the first ionization energies? (A) S < Cl < F (B) Cl < S < F (C) F < Cl < S S < F < Cl Cl < F < S 63. Which set of quantum numbers (n, l, m l, m s ) could belong to the third electron removed from an iron atom? (A) 3, 2, 3, 0 (B) 4, 3, 0, 0 (C) 3, 2, -1, -½ 3, 1, 1, -½ 4, 3, -1, ½