Test 2: Atomic Structure Review

Transcription

1 Name: Monday, October 15, 2007 Test 2: Atomic Structure Review 1. Figure 1 The diagram shows the characteristic spectral line patterns of four elements. Also shown are spectral lines produced by an unknown substance. Which pair of elements is present in the unknown? 1. lithium and sodium 3. lithium and helium 2. sodium and hydrogen 4. helium and hydrogen 2. Hydrogen has three isotopes with mass numbers of 1, 2, and 3 and has an average atomic mass of amu. This information indicates that 1. equal numbers of each isotope are present 3. more isotopes have an atomic mass of 1 than of 2 or 3 2. more isotopes have an atomic mass of 2 or 3 than of 1 4. isotopes have only an atomic mass of 1 3. A substance that is composed only of atoms having the same atomic number is classified as 1. a compound 3. a homogeneous mixture 2. an element 4. a heterogeneous mixture

2 4. What is the percent composition by mass of aluminum in Al (SO ) (gram-formula mass = 342 grams/mole)? % % % % 5. In the wave-mechanical model, an orbital is a region of space in an atom where there is 1. a high probability of finding an electron 3. a circular path in which electrons are found 2. a high probability of finding a neutron 4. a circular path in which neutrons are found 6. Which principal energy level can hold a maximum of eight electrons? Which particle has the same electron configuration as a potassium ion? 1. fluoride ion 3. neon atom 2. sodium ion 4. argon atom 8. + When a lithium atom forms an Li ion, the lithium atom 1. gains a proton 3. loses a proton 2. gains an electron 4. loses an electron

3 9. When the electrons of an excited atom return to a lower energy state, the energy emitted can result in the production of 1. alpha particles 3. protons 2. isotopes 4. spectra 10. The total number of electrons in a neutral atom of every element is always equal to the atom's 1. mass number 3. number of protons 2. number of neutrons 4. number of nucleons 11. Which substance is composed of atoms that all have the same atomic number? 1. magnesium 3. ethane 2. methane 4. ethene 12. In a sample of the element potassium, each atom has protons protons and neutrons neutrons neutrons 13. Which particles are isotopes of each other? 1. and 2. and 3. and 4. and

4 14. As a Ca atom undergoes oxidation to Ca 1. decreases 2. increases 3. remains the same 2+, the number of neutrons in its nucleus 15. Which particle has a mass of approximately one atomic mass unit and a unit positive charge? 1. a neutron 3. a beta particle 2. a proton 4. an alpha particle 16. When compared with the energy of an electron in the first shell of a carbon atom, the energy of an electron in the second shell of a carbon atom is 1. less 2. greater 3. the same 17. As an electron in an atom moves from the ground state to the excited state, the electron 1. gains energy as it moves to a higher energy level 3. loses energy as it moves to a higher energy level 2. gains energy as it moves to a lower energy level 4. loses energy as it moves to a lower energy level 18. Given the electron dot diagram: The valence electrons represented by the electron dot diagram could be those of atoms in Group (IIIA) 3. 3 (IIIB) (VA) (VIA)

5 19. Which statement best describes an electron? 1. It has a smaller mass than a proton and a negative 3. It has a greater mass than a proton and a negative charge. charge. 2. It has a smaller mass than a proton and a positive 4. It has a greater mass than a proton and a positive charge. charge. 20. Which subatomic particles are located in the nucleus of a neon atom? 1. electrons and positrons 3. protons and neutrons 2. electrons and neutrons 4. protons and electrons 21. What is the mass number of an atom that has six protons, six electrons, and eight neutrons? Base your answer on the data table, which shows three isotopes of neon. Based on natural abundances, the average atomic mass of neon is closest to which whole number?

6 23. Compared to the entire atom, the nucleus of the atom is 1. smaller and contains most of the atom's mass 3. larger and contains most of the atom's mass 2. smaller and contains little of the atom's mass 4. larger and contains little of the atom's mass 24. Rutherford's gold foil experiment illustrated that the atom 1. is mostly empty space 3. cannot be penetrated by any radiation 2. is densely packed with electrons 4. contains a negatively charged nucleus 25. A student constructs a model for comparing the masses of subatomic particles. The student selects a small, metal sphere with a mass of 1 gram to represent an electron. A sphere with which mass would be most appropriate to represent a proton? 1. 1 g 2. g 3. g g 26. The number of neutrons in the nucleus of an atom can be determined by 1. adding the atomic number to the mass number 3. adding the mass number to the atomic mass 2. subtracting the atomic number from the mass number 4. subtracting the mass number from the atomic number 27. Which statement is true about a proton and an electron? 1. They have the same masses and the same charges. 3. They have different masses and the same charges. 2. They have the same masses and different charges. 4. They have different masses and different charges.

7 28. + Potassium ions are essential to human health. The movement of dissolved potassium ions, K (aq), in and out of a nerve cell allows that cell to transmit an electrical impulse. What is the total number of electrons in a potassium ion? electrons 29. Compared to an element of calcium-40, an atom of potassium-39 contains fewer 1. protons 3. occupied sublevels 2. neutrons 4. occupied principal energy levels 30. Which species contains only 12 nucleons in the nucleus? Which is an electron configuration for an atom of chlorine in the excited state? In a calcium atom in the ground state, the electrons that possess the least amount of energy are located in the 1. first electron shell 3. third electron shell 2. second electron shell 4. fourth electron shell

8 33. The charge of a beryllium-9 nucleus is The atomic mass of an element is defined as the weighted average mass of that element's 1. most abundant isotope 3. naturally occuring isotopes 2. least abundant isotope 4. radioactive isotopes 35. Which atoms contain the same number of neutrons? 1. and 2. and 3. and 4. and 36. What is the structure of a krypton-85 atom? electrons, 49 protons, and 85 neutrons electrons, 36 protons, and 85 neutrons electrons, 49 protons, and 49 neutrons electrons, 36 protons, and 49 neutrons 37. Two isotopes of potassium are K-37 and K-42. How many valence electrons are in an atom of K-42 in the ground state? Answer: valence electron(s)

9 38. Which statement correctly describes the charge of the nucleus and the charge of the electron cloud of an atom? 1. The nucleus is positive and the electron cloud is 3. The nucleus is negative and the electron cloud is positive. positive. 2. The nucleus is positive and the electron cloud is 4. The nucleus is negative and the electron cloud is negative. negative. 39. Which particle contains the greatest number of electrons? 1. Na 3. F + 2. Na - 4. F 40. What is a possible mass number of a sodium atom? The characteristic bright-line spectrum of an atom is produced by 1. electrons absorbing quanta 3. protons absorbing quanta 2. electrons emitting quanta 4. protons emitting quanta 42. The principal quantum number of the outermost electron of an atom in the ground state is n = 3. What is the total number of occupied principal energy levels contained in this atom?

10 43. Which orbital notation correctly represents the outermost princical energy level of a nitrogen atom in the ground state? What is the total number of electrons in a completely filled fourth principal energy level? What is the approximate mass of an electron? 1. 1 atomic mass unit 3. 1/1836 of a proton 2. 1/12 of a C-12 atom /1836 of a proton 46. What is the total number of orbitals in the third principal energy level?

11 47. Energy is released when an electron changes from a sublevel of 1. 1s to 2p 3. 3s to 2s 2. 2s to 3s 4. 3p to 5s 48. Four valence electrons of an atom in the ground state would occupy the 1. s sublevel, only 3. s and p sublevels, only 2. p sublevel, only 4. s, p, and d sublevels 49. Which is a possible electron configuration for argon in the excited state? s 2s 2p 3s 3p s 2s 2p 3s 3p s 2s 2p 3s 3p s 2s 2p 3s 3p 4s 50. The total number of sublevels in the fourth principal energy level of an atom is

12 Answer Key for Test 2: Atomic Structure Review Test 2: Atomic Structure Review

13 Test 2: Atomic Structure Review