Chapter 3 Atoms and Elements 3.3 The Periodic Table Copyright © 2005 by Pearson Education, Inc. Publishing as Benjamin Cummings

Groups and Periods On the periodic table, elements are arranged according to similar properties. groups contain elements with similar properties in vertical columns. periods are horizontal rows of elements.

Groups and Periods Copyright © 2005 by Pearson Education, Inc. Publishing as Benjamin Cummings

Periodic Table Copyright © 2005 by Pearson Education, Inc. Publishing as Benjamin Cummings

Group Numbers Group Numbers use the letter A for the representative elements (1A to 8A) and the letter B for the transition elements. also use numbers 1-18 to the columns from left to right.

Names of Some Representative Elements Several groups of representative elements are known by common names. Copyright © 2005 by Pearson Education, Inc. Publishing as Benjamin Cummings

Alkali Metals Group 1A(1), the alkali metals, includes lithium, sodium, and potassium. Copyright © 2005 by Pearson Education, Inc. Publishing as Benjamin Cummings

Halogens Group 7A(17) the halogens, includes chlorine, bromine, and iodine. Copyright © 2005 by Pearson Education, Inc. Publishing as Benjamin Cummings

Learning Check Identify the element described by the following. A. Group 7A(17), Period 4 1) Br 2) Cl 3) Mn B. Group 2A(2), Period 3 1) beryllium 2) boron 3) magnesium C. Group 5A(15), Period 2 1) phosphorus 2) arsenic 3) nitrogen

Solution A. Group 7A (17), Period 4 1) Br B. Group 2A (2), Period 3 3) magnesium C. Group 5A(15), Period 2 3) nitrogen

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

Properties of Metals, Nonmetals, and Metalloids 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.

Comparing a Metal, Metalloid, and Nonmetal

Learning Check Identify each of the following elements as 1) metal 2) nonmetal 3) metalloid A. sodium ____ B. chlorine ____ C. silicon ____ D. iron ____ E. carbon ____

Solution Identify each of the following elements as 1) metal 2) nonmetal 3) metalloid A. sodium 1 metal B. chlorine 2 nonmetal C. silicon 3 metalloid D. iron 1 metal E. carbon 2 nonmetal

Learning Check 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, P 3) N, P, As, Sb C. Metalloids in Group 4A(14) 1) C, Si, Ge, 2) Si, Ge 3) Si, Ge, Sn, Pb

Solution 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