Name: Date: Atomic Structure 2017 Mrs. Mannion Version 1

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1 Name: Atomic Structure The mass of a proton is approximately equal to the mass of A) a beta particle B) an electron C) an alpha particle D) a neutron 2. What are the characteristics of a neutron? A) It has no charge and no mass. B) It has no charge and a mass of 1 amu. C) It has a charge of +l and a mass of 1 amu. D) It has a charge of +1 and no mass. 3. An atom in the ground state has two electrons in its first shell and six electrons in its second shell. What is the total number of protons in the nucleus of this atom? A) 5 B) 2 C) 7 D) 8 4. A neutron has a charge of A) +1 B) +2 C) 0 D) 1 5. What is the charge and mass of a proton? A) charge of +1 and mass of 1 amu B) charge of 1 and mass of 1 amu C) charge of 1 and mass of amu D) charge of +1 and mass of amu 6. In Rutherford's gold foil experiments, some alpha particles were deflected from their original paths but most passed through the foil with no deflection. Which statement about gold atoms is supported by these experimental observations? A) Gold atoms consist mostly of empty space. B) Alpha particles and gold nuclei have opposite charges. C) Gold atoms are similar to alpha particles. D) Alpha particles are more dense than gold atoms. 7. Which conclusion was a direct result of the gold foil experiment? A) An atom is mostly empty space with a dense, positively charged B) An atom is composed of at least three types of subatomic particles. C) An electron has a positive charge and is located inside the D) An electron has properties of both waves and particles. Date: Mrs. Mannion 8. Which statement describes the distribution of charge in an atom? A) A neutral nucleus is surrounded by one or more positively charged electrons. B) A positively charged nucleus is surrounded by one or more positively charged electrons. C) A neutral nucleus is surrounded by one or more negatively charged electrons. D) A positively charged nucleus is surrounded by one or more negatively charged electrons. 9. An atom of any element must contain A) an equal number of protons and neutrons B) an equal number of protons and electrons C) more electrons than neutrons D) more electrons than protons 10. How many protons are in the nucleus of an atom of beryllium, Be? A) 5 B) 2 C) 9 D) As the number of neutrons in the nucleus of a given atom of an element increases, the atomic number of that element A) decreases B) increases C) remains the same 12. Which of the following atoms has the greatest nuclear charge? A) B) C) D) 13. What is the mass number of 19 9F? A) 28 B) 10 C) 19 D) The atomic mass of magnesium is the weighted average of the atomic masses of A) all of the artificially produced isotopes of Mg B) all of the naturally occurring isotopes of Mg C) the two most abundant naturally occurring isotopes of Mg D) the two most abundant artificially produced isotopes of Mg 15. An atom that has 13 protons and 15 neutrons is an isotope of the element A) nickel B) aluminum C) silicon D) phosphorus

2 16. Which symbols represent atoms that are isotopes of each other? A) 14 C and 14 N B) 222 Rn and 222 Ra C) 16 O and 18 O D) 131 I and 131 I 17. The nucleus of an atom of K-42 contains A) 19 protons and 23 neutrons B) 23 protons and 19 neutrons C) 20 protons and 19 neutrons D) 19 protons and 42 neutrons 18. Which isotopic notation represents an atom of carbon-14? A) 6 14C B) 6 8C C) 8 6C D) 14 6C 19. Each diagram below represents the nucleus of a different atom. Which diagrams represent nuclei of the same element? A) Q and R, only B) D, E, and Q C) Q, R, and E D) D and E, only 20. Some information about the two naturally occurring isotopes of gallium is given in the table below. 22. An orbital is defined as a region of the most probable location of A) an electron B) a neutron C) a proton D) a nucleus 23. The electron configuration of an atom in the ground state is 2-4. The total number of occupied principal energy levels in this atom is A) 1 B) 2 C) 3 D) What is the electron configuration for Be 2+ ions? A) 2 B) 2-1 C) 1 D) Which electron configuration is possible for a nitrogen atom in the excited state? A) 2-5 B) 2-4 C) 2-6 D) What causes the emission of radiant energy that produces characteristic spectral lines? A) gamma ray emission from the nucleus B) return of electrons to lower energy levels C) neutron absorption by the nucleus D) movement of electrons to higher energy levels Which numerical setup can be used to calculate the atomic mass of gallium? A) (0.6011)( u) + (0.3989)( u) B) (60.11)( u) + (39.89)( u) C) (0.6011)( u) + (0.3989)( u) D) (60.11)( u) + (39.89)( u)a 21. What is the maximum number of electrons in the third shell of an atom? A) 6 B) 9 C) 3 D) 18

3 27. The diagram below represents the bright-line spectra of four elements and a bright-line spectrum produced by a mixture of two of these elements. Which two elements are in this mixture? A) helium and lithium B) barium and lithium C) barium and hydrogen D) helium and hydrogen 28. What is the total number of occupied sublevels in the third principal energy level of a zinc atom in the ground state? A) 1 B) 2 C) 3 D) Which statement describes a concept included in the wave-mechanical model of the atom? A) Positrons are located in shells outside the B) Electrons are located in orbitals outside the C) Neutrons are located in shells outside the D) Protons are located in orbitals outside the 30. Compared to the energy and charge of the electrons in the first shell of a Be atom, the electrons in the second shell of this atom have A) less energy and a different charge B) more energy and the same charge C) less energy and the same charge D) more energy and a different charge 31. Which atom in the ground state has the same electron configuration as a calcium ion, Ca 2+, in the ground state? A) K B) Ar C) Ne D) Mg

4 32. Base your answer to the following question on the information and diagram below. One model of the atom states that atoms are tiny particles composed of a uniform mixture of positive and negative charges. Scientists conducted an experiment where alpha particles were aimed at a thin layer of gold atoms. Most of the alpha particles passed directly through the gold atoms. A few alpha particles were deflected from their straight-line paths. An illustration of the experiment is shown below. A few of the alpha particles were deflected. What does this evidence suggest about the structure of the gold atoms? 33. Explain, in terms of protons and neutrons, why U-235 and U-238 are different isotopes of uranium. 34. Base your answer to the following question on the information below An atom in an excited state has an electron configuration of Explain, in terms of subatomic particles, why this excited atom is electrically neutral. 35. Describe the electrons in an atom of carbon in the ground state. Your response must include: the charge of an electron the location of electrons based on the wave-mechanical model the total number of electrons in a carbon atom

5 36. Base your answer to the following question on the information below. The bright-line spectra for three elements and a mixture of elements are shown below. Explain, in terms of both electrons and energy, how the bright-line spectrum of an element is produced. 37. In nature, 1.07% of the atoms in a carbon sample are C-13 atoms. Show a numerical setup for calculating the number of C-13 atoms in a sample containing atoms of carbon.

6 38. Base your answer to the following question on the information below and on your knowledge of chemistry. The bright-line spectra observed in a spectroscope for three elements and a mixture of two of these elements are represented in the diagram below. Describe, in terms of both electrons and energy state, how the light represented by the spectral lines is produced.