Download presentation
Presentation is loading. Please wait.
Published byVivien Perry Modified over 9 years ago
1
General, Organic, and Biological Chemistry Fourth Edition Karen Timberlake 3.7 Orbital Diagrams and Electron Configurations Chapter 3 Atoms and Elements © 2013 Pearson Education, Inc. Lectures
2
© 2013 Pearson Education, Inc. Chapter 3, Section 7 Order of Filling Energy levels are filled with electrons in order of increasing energy. beginning with quantum number n = 1. beginning with s followed by p, d, and f in each energy level. 2
3
© 2013 Pearson Education, Inc. Chapter 3, Section 7 Energy Diagram for Sublevels 3
4
© 2013 Pearson Education, Inc. Chapter 3, Section 7 Orbital Diagrams 4 An orbital diagram shows orbitals as boxes in each sublevel. electrons in orbitals as vertical arrows. electrons in the same orbital with opposite spins (up and down vertical arrows). Example: Orbital diagram for Li 1s 2 filled 2s 1 half-filled 2p empty
5
© 2013 Pearson Education, Inc. Chapter 3, Section 7 Order of Filling Electrons in an atom fill the lowest energy level and orbitals first, fill orbitals in a particular sublevel with one electron each until all orbitals are half full, and then fill each orbital using electrons with opposite spins. 5
6
© 2013 Pearson Education, Inc. Chapter 3, Section 7 Writing Orbital Diagrams 6 The orbital diagram for carbon has 6 electrons: 2 electrons are used to fill the 1s orbital. 2 more electrons are used to fill the 2s orbital. 1 electron is used in two of the 2p orbitals so they are half-filled, leaving one p orbital empty. Electron arrangements in orbitals in energy levels 1 and 2.
7
© 2013 Pearson Education, Inc. Chapter 3, Section 7 Learning Check Write the orbital diagrams for each of the following: 1. nitrogen 2. oxygen 3. magnesium 7
8
© 2013 Pearson Education, Inc. Chapter 3, Section 7 Solution 8 Write the orbital diagrams for each of the following: 1. nitrogen 1s 2s 2p 2. oxygen 1s 2s 2p 3. magnesium 1s 2s 2p 3s
9
© 2013 Pearson Education, Inc. Chapter 3, Section 7 Electron Configuration An electron configuration lists the filled and partially filled energy levels in order of increasing energy. lists the sublevels filling with electrons in order of increasing energy. uses superscripts to show the number of electrons in each sublevel. for neon is as follows: number of electrons = 10 1s 2 2s 2 2p 6 9
10
© 2013 Pearson Education, Inc. Chapter 3, Section 7 Period 1 Configurations 10 In Period 1, the first two electrons enter the 1s orbital.
11
© 2013 Pearson Education, Inc. Chapter 3, Section 7 Period 2 Configurations 11 In Period 2, lithium has 3 electrons –2 in the 1s and 1 in the 2s. beryllium has 4 electrons –2 in the 1s and 2 in the 2s. boron has 5 electrons –2 in the 1s, 2 in the 2s, and 1 in the 2p. carbon has 6 electrons –2 in the 1s, 2 in the 2s, and 2 in the 2p.
12
© 2013 Pearson Education, Inc. Chapter 3, Section 7 Abbreviated Configurations In an abbreviated configuration, the symbol of the noble gas is in brackets, representing completed sublevels. the remaining electrons are listed in order of their sublevels. Example: Chlorine has the following configuration: 1s 2 2s 2 2p 6 3s 2 3p 5 [Ne] The abbreviated configuration for chlorine is [Ne]3s 2 3p 5. 12
13
© 2013 Pearson Education, Inc. Chapter 3, Section 7 Period 2 Configurations 13
14
© 2013 Pearson Education, Inc. Chapter 3, Section 7 Period 3 Configurations 14
15
© 2013 Pearson Education, Inc. Chapter 3, Section 7 Learning Check 1. The correct electron configuration for nitrogen is A. 1s 2 2p 5 B. 1s 2 2s 2 2p 6 C. 1s 2 2s 2 2p 3 2. The correct electron configuration for oxygen is A. 1s 2 2p 6 B. 1s 2 2s 2 2p 4 C. 1s 2 2s 2 2p 6 3. The correct electron configuration for calcium is A. 1s 2 2s 2 2p 6 3s 2 3p 6 3d 2 B. 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 C. 1s 2 2s 2 2p 6 3s 2 3p 8 15
16
© 2013 Pearson Education, Inc. Chapter 3, Section 7 Solution 1. The correct electron configuration for nitrogen is C. 1s 2 2s 2 2p 3 2. The correct electron configuration for oxygen is B. 1s 2 2s 2 2p 4 3. The correct electron configuration for calcium is B. 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 16
17
© 2013 Pearson Education, Inc. Chapter 3, Section 7 Learning Check Write the electron configuration and abbreviated configuration for each of the following elements: 1. Cl 2. S 3. K 17
18
© 2013 Pearson Education, Inc. Chapter 3, Section 7 Solution Write the electron configuration and abbreviated configuration for each of the following elements: 1. Cl 1s 2 2s 2 2p 6 3s 2 3p 5 [Ne]3s 2 3p 5 2. S 1s 2 2s 2 2p 6 3s 2 3p 4 [Ne]3s 2 3p 4 3. K 1s 2 2s 2 2p 6 3s 2 3p 6 4s 1 [Ar]4s 1 18
19
© 2013 Pearson Education, Inc. Chapter 3, Section 7 Electron Configurations and the Periodic Table The periodic table consists of sublevel blocks arranged in order of increasing energy. Groups 1A and 2A= s block Groups 3A to 8A= p block Transition Elements (This sublevel is (n-1), 1 less than the period number.)= d block Lanthanides/Actinides (This sublevel is (n-2), 2 less than the period number.)= f block 19
20
© 2013 Pearson Education, Inc. Chapter 3, Section 7 Sublevel Blocks 20
21
© 2013 Pearson Education, Inc. Chapter 3, Section 7 Guide to Using Sublevel Blocks 21
22
© 2013 Pearson Education, Inc. Chapter 3, Section 7 Writing Electron Configurations Using the periodic table, write the electron configuration for silicon. Solution: Period 11s block1s 2 Period 22s → 2p blocks 2s 2 2p 6 Period 3 3s → 3p blocks 3s 2 3p 2 (at Si) Writing all the sublevel blocks in order gives the following: 1s 2 2s 2 2p 6 3s 2 3p 2 22
23
© 2013 Pearson Education, Inc. Chapter 3, Section 7 Electron Configurations of the d Level The 4s orbital has a lower energy than the 3d orbitals. 23
24
© 2013 Pearson Education, Inc. Chapter 3, Section 7 Writing Electron Configurations Using the periodic table, write the electron configuration for manganese. Solution: Period 11s block1s 2 Period 22s → 2p block 2s 2 2p 6 Period 3 3s → 3p block 3s 2 3p 6 Period 44s → 3d block4s 2 3d 5 (at Mn) Writing all the sublevel blocks in order gives the following: 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 5 24
25
© 2013 Pearson Education, Inc. Chapter 3, Section 7 Learning Check 1. What are the last two sublevel blocks in the electron configuration for Co? A. 3p 6 4s 2 B. 4s 2 4d 7 C. 4s 2 3d 7 2. What are the last three sublevel blocks in the electron configuration for Sn? A. 5s 2 5p 2 4d 10 B. 5s 2 4d 10 5p 2 C. 5s 2 5d 10 5p 2 25
26
© 2013 Pearson Education, Inc. Chapter 3, Section 7 Solution 1. What are the last two sublevel blocks in the electron configuration for Co? C. 4s 2 3d 7 2. What are the last three sublevel blocks in the electron configuration for Sn? B. 5s 2 4d 10 5p 2 26
27
© 2013 Pearson Education, Inc. Chapter 3, Section 7 Learning Check Using the periodic table, write the electron configuration and abbreviated configuration for each of the following elements: 1. Zn 2. Sr 3. I 27
28
© 2013 Pearson Education, Inc. Chapter 3, Section 7 Solution 1. Zn 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 [Ar]4s 2 3d 10 2. Sr 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 [Kr]5s 2 3. I 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 4d 10 5p 5 [Kr]5s 2 4d 10 5p 5 28
29
© 2013 Pearson Education, Inc. Chapter 3, Section 7 Learning Check Give the symbol of the element that has 1. the abbreviated configuration [Ar]4s 2 3d 6. 2. four 3p electrons. 3. two electrons in the 4d sublevel. 4. the electron configuration 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 2. 29
30
© 2013 Pearson Education, Inc. Chapter 3, Section 7 Solution Give the symbol of the element that has 1. the abbreviated configuration [Ar]4s 2 3d 6. Fe 2. four 3p electrons. S 3. two electrons in the 4d sublevel. Zr 4. the electron configuration Ti 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 2. 30
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.