1. 1 Chapter 3 Electronic Structure and the Periodic Law 3.5 Another Look at the Periodic Table Copyright © 2005 by Pearson Education, Inc. Publishing as Benjamin Cummings

2. 2 Distinguishing Electrons The last and highest energy electron found in an element. Nobel gas configurations can be used to write abbreviated electronic configurations. Instead of writing the configurations in their entirety, the symbols for the noble gases are used in brackets to represent the electrons found in their configuration.

3. 3 Abbreviated Electronic Configuration Form For example, take Group 1A(1), which contains Li, Na, K, Rb, Cs, and Fr with the electronic configuration for the first four elements shown below. Element Symbol Conventional Form Li1s 2,2s 1 Na1s 2,2s 2,2p 6,3s 1 K1s 2,2s 2,2p 6,3s 1,3p 6,4s 1 Rb1s 2,2s 2,2p 6,3s 1,3p 6,4s 2,3d 10,4p 6,5s 1

4. 4 Abbreviated Electronic Configuration Form Element Symbol Conventional Form Li1s 2,2s 1 Na1s 2,2s 2,2p 6,3s 1 K1s 2,2s 2,2p 6,3s 1,3p 6,4s 1 Rb1s 2,2s 2,2p 6,3s 1,3p 6,4s 2, 3d 10,4p 6,5s 1 The abbreviated form can be written using the noble gas configuration as a shorthand notation in brackets. Abbreviated Form [He]2s 1 [Ne]3s 1 [Ar]4s 1 [Kr]5s 1

5. 5 Abbreviated Electronic Configuration Form Element Symbol Conventional Form Li1s 2,2s 1 Na1s 2,2s 2,2p 6,3s 1 K1s 2,2s 2,2p 6,3s 1,3p 6,4s 1 Rb1s 2,2s 2,2p 6,3s 1,3p 6,4s 2,3d 10,4p 6,5s 1 Notice that each of these elements has a single electron in the valence shell, is located in the s subshell, and similar chemical properties of elements in the same group.

6. 6 Periodic Table divided into subshells Copyright © 2005 by Pearson Education, Inc. Publishing as Benjamin Cummings s subshells d subshellsp subshells f subshells

7. 7 Metals, Nonmetals, and Metalloids The heavy zigzag line separates metals and nonmetals. Metals are located to the left. Nonmetals are located to the right. Metalloids are located along the heavy zigzag line between the metals and nonmetals. Copyright © 2005 by Pearson Education, Inc. Publishing as Benjamin Cummings

8. 8 Metals are shiny and ductile. are good conductors of heat and electricity. Nonmetals are dull, brittle, and poor conductors. are good insulators. Metalloids are better conductors than nonmetals, but not as good as metals. are used as semiconductors and insulators. Properties of Metals, Nonmetals, and Metalloids

9. 9 Comparing a Metal, Metalloid, and Nonmetal

10. 10 Identify each of the following elements as 1) metal 2) nonmetal 3) metalloid A. sodium____ B. chlorine____ C. silicon ____ D. iron____ E. carbon____ Learning Check

11. 11 Identify each of the following elements as 1) metal 2) nonmetal 3) metalloid A. sodium1 metal B. chlorine2 nonmetal C. silicon 3 metalloid D. iron1 metal E. carbon2 nonmetal Solution

12. 12 Match the elements to the description. A. Metals in Group 4A(14) 1) Sn, Pb 2) C, Si 3) C, Si, Ge, Sn B. Nonmetals in Group 5A(15) 1) As, Sb, Bi 2) N, P3) N, P, As, Sb C. Metalloids in Group 4A(14) 1) C, Si, Ge, 2) Si, Ge 3) Si, Ge, Sn, Pb Learning Check

13. 13 Match the elements to the description. A. Metals in Group 4A (14) 1) Sn, Pb B. Nonmetals in Group 5A(15) 2) N, P C. Metalloids in Group 4A(14) 2) Si, Ge Solution