Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Name ___________________________ Date ___________________ Class __________________ MODELS OF THE ATOM 5.1 Section Review Objectives • Identify inadequacies in the Rutherford atomic model • Identify the new assumption in the Bohr model of the atom • Describe the energies and positions of electrons according to the quantum mechanical model • Describe how the shapes of orbitals at different sublevels vary Vocabulary • energy levels • quantum • quantum mechanical model • atomic orbital Part A Completion Use this completion exercise to check your understanding of the concepts and terms that are introduced in this section. Each blank can be completed with a term, short phrase, or number. 1. The chemical properties of atoms, ions, and molecules © Pearson Education, Inc., publishing as Pearson Prentice Hall. All rights reserved. are related to the arrangement of the 1 2. within them. 2 The first modern atomic theory, proposed by 3. , portrayed the atom as a solid, indivisible mass. After the discovery of the electron by 3 , the atomic model was revised to 4 include them. J.J. Thomson’s model is referred to as the model. Rutherford pictured the atom as a dense 6 paths. The 7 5. 6. 5 7. surrounded by electrons. In the Bohr model, the electrons move in 4. 8. model is the modern description of the electrons in atoms. This model estimates the 8 of finding an electron within a certain volume of space surrounding the nucleus. Part B True-False Classify each of these statements as always true, AT; sometimes true, ST; or never true, NT. ________ 9. Electrons must have a certain minimum amount of energy called a quantum in order to move from one energy level to the next higher energy level. ________ 10. The electron probability clouds for atomic orbitals are spherical in shape. Chapter 5 Electrons in Atoms 105 Name ________________________________________ Class _________________ Date _______________ ________ 11. The number of sublevels in an energy level is equal to the square of the principal quantum number of that energy level. ________ 12. The maximum number of electrons that can occupy the fourth principal energy level of an atom is 32. ________ 13. The higher the energy level occupied by an electron the more energetic it is. ________ 14. The principal quantum number equals the number of sublevels within that principal energy level. Part C Matching Match each description in Column B to the correct term in Column A. Column A Column B ________ 15. quantum a. a region in space around the nucleus of an atom where an electron is likely to be moving ________ 16. atomic orbitals b. the regions around the nucleus within which the electrons have the highest probability of being found ________ 17. energy level c. the amount of energy required to move an electron from its present energy level to the next higher one ________ 18. quantum mechanical model d. the modern description of the behavior of electrons in atoms Part D Questions and Problems Answer the following in the space provided. 20. How many orbitals are in each of the following sublevels? a. 4p sublevel b. 3d sublevel c. 4f sublevel d. 2s sublevel 106 Core Teaching Resources Prentice Hall, Inc. All rights reserved. 19. Summarize the development of atomic theory. Name ___________________________ Date ___________________ Class __________________ ELECTRON ARRANGEMENT IN ATOMS 5.2 Section Review Objectives • Describe how to write the electron configuration for an atom • Explain why the actual electron configurations for some elements differ from those predicted by the Aufbau principle Vocabulary • electron configurations • Aufbau principle • Pauli exclusion principle • Hund’s rule Part A Completion Use this completion exercise to check your understanding of the concepts and terms that are introduced in this section. Each blank can be completed with a term, short phrase, or number. 1. The ways in which electrons are arranged around the nuclei of atoms are called 1 . The 2 2. describes the sequence 3. © Pearson Education, Inc., publishing as Pearson Prentice Hall. All rights reserved. in which orbitals are filled. The various orbitals within a sublevel of a principle energy level are always of 4 3 4. energy. The principle states that a maximum of only 5 5. electrons can occupy each orbital. To occupy the same orbital, two electrons must have 6 spins. Hund’s rule states that the electrons pair up only after each orbital in a sublevel is occupied 7 by . When using the shorthand method for showing the electron configuration of an atom, the number of 9 8 are used to indicate 6. 7. 8. 9. 10. occupying each sublevel. Correct electron configurations can be obtained by using the Aufbau diagram for the elements up to and including vanadium. 10 and copper are exceptions to the Aufbau principle. Chapter 5 Electrons in Atoms 107 Name ________________________________________ Class _________________ Date _______________ Part B True-False Classify each of these statements as always true, AT; sometimes true, ST; or never true, NT. ________ 11. The orbitals of a principal energy level are lower in energy than the orbitals in the next higher principal energy level. ________ 12. The configuration 3d 44s2 is more stable than the configuration 3d 54s1. ________ 13. As many as four electrons can occupy the same orbital. ________ 14. The Pauli exclusion principle states that an atomic orbital may describe at most two electrons. ________ 15. The electron configuration for potassium is 1s22s22p6 3s23p64s1. ________ 16. The electron configuration for copper is 1s22s22p63s23p64s23d 9. Part C Matching Match each description in Column B to the correct term in Column A. Column B ________ 17. electron configuration a. When electrons occupy orbitals of equal energy, one electron enters each orbital until all the orbitals contain one electron with parallel spins. ________ 18. Aufbau principle b. An atomic orbital may describe at most two electrons. ________ 19. Pauli exclusion principle c. 1s22s22p6 ________ 20. Hund’s rule d. Electrons enter orbitals of lowest energy first. ________ 21. neon e. the most stable arrangement of electrons around the nucleus of an atom Part D Questions and Problems Answer the following in the space provided. 22. Write the electron configurations for the following atoms. a. C c. K b. S d. Ar 23. Identify the elements described below: a. Contains a full third energy level. b. Contains the first p electron. 108 Core Teaching Resources Prentice Hall, Inc. All rights reserved. Column A Name ___________________________ 5.3 Date ___________________ Class __________________ PHYSICS AND THE QUANTUM MECHANICAL MODEL Section Review Objectives • • • • Describe the relationship between the wavelength and frequency of light Explain how the frequencies of light are related to changes in electron energies Distinguish between quantum mechanics and classical mechanics Identify the cause of the atomic emission spectrum Vocabulary • • • • • • • • amplitude wavelength (") frequency (#) hertz (Hz) electromagnetic radiation spectrum • photons • Heisenberg uncertainty principle atomic emission spectrum ground state Key Equations • c ! "# • E!h$# h m# © Pearson Education, Inc., publishing as Pearson Prentice Hall. All rights reserved. • " ! %% Part A Completion Use this completion exercise to check your understanding of the concepts and terms that are introduced in this section. Each blank can be completed with a term, short phrase, or number. According to quantum mechanics, the motions of subatomic 1 particles may be described as 2 wavelength of all waves are Every element emits . The frequency and if it is heated by passing an electric discharge through its gas or vapor. Passing this emission through a prism gives the 4 and Einstein's explanation of the 6 4. 5. 6. of the element. The quantum concept developed from Planck’s studies of 5 2. 3. related. 3 1. 7. effect. Planck showed that the amount of radiant energy absorbed or emitted by a body is proportional to the 7 of the radiation. Chapter 5 Electrons in Atoms 109 Name ________________________________________ Class _________________ Date _______________ Part B True-False Classify each of these statements as always true, AT; sometimes true, ST; or never true, NT. ________ 8. The speed of light is a constant that can be obtained by dividing the frequency of light by its wavelength. ________ 9. The amplitude of a wave is the distance between the crests. ________ 10. The energy of a body can change only in small discrete units. ________ 11. The position and velocity of an electron in an atom can be determined with great certainty. ________ 12. The photoelectric effect will occur no matter what frequency of light strikes a metal. Part C Matching Match each description in Column B to the correct term in Column A. Column A Column B ________ 13. photons a. predicts that all matter exhibits wavelike motions ________ 14. de Broglie’s equation b. the distance between two consecutive wave crests ________ 15. visible light c. light quanta ________ 16. ground state d. the lowest energy level for a given electron ________ 17. wavelength e. example of electromagnetic radiation Part D Questions and Problems Answer the following in the space provided. 19. Apply quantum theory to explain the photoelectric effect. 110 Core Teaching Resources Prentice Hall, Inc. All rights reserved. 18. What is the frequency of radiation whose wavelength is 2.40 ! 10"5 cm?