Periodicity

Introduction

Three photos are shown. The first shows a scientific lab full of equipment in which two people in protective suits are working. The second image shows a man holding a round, reflective disc held inside of a protective, clear container. The third image shows a round disc covered in metallic chips which is behind a protective covering.

Purity is extremely important when preparing silicon wafers. Technicians in a cleanroom prepare silicon without impurities (left). The CEO of VLSI Research, Don Hutcheson, shows off a pure silicon wafer (center). A silicon wafer covered in Pentium chips is an enlarged version of the silicon wafers found in many electronics used today (right). (credit middle: modification of work by “Intel Free Press”/Flickr; credit right: modification of work by Naotake Murayama)

The development of the periodic table in the mid-1800s came from observations that there was a periodic relationship between the properties of the elements. Chemists, who have an understanding of the variations of these properties, have been able to use this knowledge to solve a wide variety of technical challenges. For example, silicon and other semiconductors form the backbone of modern electronics because of our ability to fine-tune the electrical properties of these materials. This tutorial explores important properties of representative metals, metalloids, and nonmetals in the periodic table.

Periodicity

We begin this topic by examining the behaviors of representative metals in relation to their positions in the periodic table. The primary focus of this topic will be the application of periodicity to the representative metals.

It is possible to divide elements into groups according to their electron configurations. The representative elements are elements where the s and p orbitals are filling. The transition elements are elements where the d orbitals (groups 3–11 on the periodic table) are filling, and the inner transition metals are the elements where the f orbitals are filling.

The d orbitals fill with the elements in group 11; therefore, the elements in group 12 qualify as representative elements because the last electron enters an s orbital. Metals among the representative elements are the representative metals. Metallic character results from an element’s ability to lose its outer valence electrons and results in high thermal and electrical conductivity, among other physical and chemical properties.

There are 20 nonradioactive representative metals in groups 1, 2, 3, 12, 13, 14, and 15 of the periodic table (the elements shaded in yellow in the figure below). The radioactive elements copernicium, flerovium, polonium, and livermorium are also metals but are beyond the scope of this tutorial.

In addition to the representative metals, some of the representative elements are metalloids. A metalloid is an element that has properties that are between those of metals and nonmetals; these elements are typically semiconductors.

The remaining representative elements are nonmetals. Unlike metals, which typically form cations and ionic compounds (containing ionic bonds), nonmetals tend to form anions or molecular compounds. In general, the combination of a metal and a nonmetal produces a salt. A salt is an ionic compound consisting of cations and anions.

The Periodic Table of Elements is shown. The 18 columns are labeled “Group” and the 7 rows are labeled “Period.” Below the table to the right is a box labeled “Color Code” with different colors for representative metals, transition and inner transition metals, radioactive elements, metalloids, and nonmetals, as well as solids, liquids, and gases. Each element will be described in this order: atomic number; name; symbol; whether it is a representative metal, transition and inner transition metal, radioactive element, metalloid, or nonmetal; whether it is a solid, liquid, or gas; and atomic mass. Beginning at the top left of the table, or period 1, group 1, is a box containing “1; hydrogen; H; nonmetal; gas; and 1.008.” There is only one other element box in period 1, group 18, which contains “2; helium; H e; nonmetal; gas; and 4.003.” Period 2, group 1 contains “3; lithium; L i; representative metal; solid; and 6.94” Group 2 contains “4; beryllium; B e; representative metal; solid; and 9.012.” Groups 3 through 12 are skipped and group 13 contains “5; boron; B; metalloid; solid; 10.81.” Group 14 contains “6; carbon; C; nonmetal; solid; and 12.01.” Group 15 contains “7; nitrogen; N; nonmetal; gas; and 14.01.” Group 16 contains “8; oxygen; O; nonmetal; gas; and 16.00.” Group 17 contains “9; fluorine; F; nonmetal; gas; and 19.00.” Group 18 contains “10; neon; N e; nonmetal; gas; and 20.18.” Period 3, group 1 contains “11; sodium; N a; representative metal; solid; and 22.99.” Group 2 contains “12; magnesium; M g; representative metal; solid; and 24.31.” Groups 3 through 12 are skipped again in period 3 and group 13 contains “13; aluminum; A l; representative metal; solid; and 26.98.” Group 14 contains “14; silicon; S i; metalloid; solid; and 28.09.” Group 15 contains “15; phosphorous; P; nonmetal; solid; and 30.97.” Group 16 contains “16; sulfur; S; nonmetal; solid; and 32.06.” Group 17 contains “17; chlorine; C l; nonmetal; gas; and 35.45.” Group 18 contains “18; argon; A r; nonmetal; gas; and 39.95.” Period 4, group 1 contains “19; potassium; K; representative metal; solid; and 39.10.” Group 2 contains “20; calcium; C a; representative metal; solid; and 40.08.” Group 3 contains “21; scandium; S c; transition and inner transition metal; solid; and 44.96.” Group 4 contains “22; titanium; T i; transition and inner transition metal; solid; and 47.87.” Group 5 contains “23; vanadium; V; transition and inner transition metal; solid; and 50.94.” Group 6 contains “24; chromium; C r; transition and inner transition metal; solid; and 52.00.” Group 7 contains “25; manganese; M n; transition and inner transition metal; solid; and 54.94.” Group 8 contains “26; iron; F e; transition and inner transition metal; solid; and 55.85.” Group 9 contains “27; cobalt; C o; transition and inner transition metal; solid; and 58.93.” Group 10 contains “28; nickel; N i; transition and inner transition metal; solid; and 58.69.” Group 11 contains “29; copper; C u; transition and inner transition metal; solid; and 63.55.” Group 12 contains “30; zinc; Z n; transition and inner transition metal; solid; and 65.38.” Group 13 contains “31; gallium; G a; representative metal; solid; and 69.72.” Group 14 contains “32; germanium; G e; metalloid; solid; and 72.63.” Group 15 contains “33; arsenic; A s; metalloid; solid; and 74.92.” Group 16 contains “34; selenium; S e; nonmetal; solid; and 78.97.” Group 17 contains “35; bromine; B r; nonmetal; liquid; and 79.90.” Group 18 contains “36; krypton; K r; nonmetal; gas; and 83.80.” Period 5, group 1 contains “37; rubidium; R b; representative metal; solid; and 85.47.” Group 2 contains “38; strontium; S r; representative metal; solid; and 87.62.” Group 3 contains “39; yttrium; Y; transition and inner transition metal; solid; and 88.91.” Group 4 contains “40; zirconium; Z r; transition and inner transition metal; solid; and 91.22.” Group 5 contains “41; niobium; N b; transition and inner transition metal; solid; and 92.91.” Group 6 contains “42; molybdenum; M o; transition and inner transition metal; solid; and 95.95.” Group 7 contains “43; technetium; T c; radioactive element; solid; and 97.” Group 8 contains “44; ruthenium; R u; transition and inner transition metal; solid; and 101.1.” Group 9 contains “45; rhodium; R h; transition and inner transition metal; solid; and 102.9.” Group 10 contains “46; palladium; P d; transition and inner transition metal; solid; and 106.4.” Group 11 contains “47; silver; A g; transition and inner transition metal; solid; and 107.9.” Group 12 contains “48; cadmium; C d; transition and inner transition metal; solid; and 112.4.” Group 13 contains “49; indium; I n; representative metal; solid; and 114.8.” Group 14 contains “50; tin; S n; representative metal; solid; and 118.7.” Group 15 contains “51; antimony; S b; metalloid; solid; and 121.8.” Group 16 contains “52; tellurium; T e; metalloid; solid; and 127.6.” Group 17 contains “53; iodine; I; nonmetal; solid; and 126.9.” Group 18 contains “54; xenon; X e; nonmetal; gas; and 131.3.” Period 6, group 1 contains “55; cesium; C s; representative metal; solid; and 132.9.” Group 2 contains “56; barium; B a; representative metal; solid; and 137.3.” Group 3 breaks the pattern. The box has a large arrow pointing to a row of elements below the table with atomic numbers ranging from 57-71. In sequential order by atomic number, the first box in this row contains “57; lanthanum; L a; representative metal; solid; and 138.9.” To its right, the next is “58; cerium; C e; representative metal; solid; and 140.1.” Next is “59; praseodymium; P r; representative metal; solid; and 140.9.” Next is “60; neodymium; N d; representative metal; solid; and 144.2.” Next is “61; promethium; P m; radioactive element; solid; and 145.” Next is “62; samarium; S m; representative metal; solid; and 150.4.” Next is “63; europium; E u; representative metal; solid; and 152.0.” Next is “64; gadolinium; G d; representative metal; solid; and 157.3.” Next is “65; terbium; T b; representative metal; solid; and 158.9.” Next is “66; dysprosium; D y; representative metal; solid; and 162.5.” Next is “67; holmium; H o; representative metal; solid; and 164.9.” Next is “68; erbium; E r; representative metal; solid; and 167.3.” Next is “69; thulium; T m; representative metal; solid; and 168.9.” Next is “70; ytterbium; Y b; representative metal; solid; and 173.1.” The last in this special row is “71; lutetium; L u; representative metal; solid; and 175.0.” Continuing in period 6, group 4 contains “72; hafnium; H f; transition and inner transition metal; solid; and 178.5.” Group 5 contains “73; tantalum; T a; transition and inner transition metal; solid; and 180.9.” Group 6 contains “74; tungsten; W; transition and inner transition metal; solid; and 183.8.” Group 7 contains “75; rhenium; R e; transition and inner transition metal; solid; and 186.2.” Group 8 contains “76; osmium; O s; transition and inner transition metal; solid; and 190.2.” Group 9 contains “77; iridium; I r; transition and inner transition metal; solid; and 192.2.” Group 10 contains “78; platinum; P t; transition and inner transition metal; solid; and 195.1.” Group 11 contains “79; gold; A u; transition and inner transition metal; solid; and 197.0.” Group 12 contains “80; mercury; H g; transition and inner transition metal; liquid; and 200.6.” Group 13 contains “81; thallium; T l; representative metal; solid; and 204.4.” Group 14 contains “82; lead; P b; representative metal; solid; and 207.2.” Group 15 contains “83; bismuth; B i; representative metal; solid; and 209.0.” Group 16 contains “84; polonium; P o; radioactive element; solid; and 209.” Group 17 contains “85; astatine; A t; radioactive element; solid; and 210.” Group 18 contains “86; radon; R n; radioactive element; gas; and 222.” Period 7, group 1 contains “87; francium; F r; radioactive element; solid; and 223.” Group 2 contains “88; radium; R a; radioactive element; solid; and 226.” Group 3 breaks the pattern much like what occurs in period 6. A large arrow points from the box in period 7, group 3 to a special row containing the elements with atomic numbers ranging from 89-103, just below the row which contains atomic numbers 57-71. In sequential order by atomic number, the first box in this row contains “89; actinium; A c; radioactive element; solid; and 227.” To its right, the next is “90; thorium; T h; radioactive element; solid; and 232.0.” Next is “91; protactinium; P a; radioactive element; solid; and 231.0.” Next is “92; uranium; U; radioactive element; solid; and 238.0.” Next is “93; neptunium; N p; radioactive element; solid; and N p.” Next is “94; plutonium; P u; radioactive element; solid; and 244.” Next is “95; americium; A m; radioactive element; solid; and 243.” Next is “96; curium; C m; radioactive element; solid; and 247.” Next is “97; berkelium; B k; radioactive element; solid; and 247.” Next is “98; californium; C f; radioactive element; solid; and 251.” Next is “99; einsteinium; E s; radioactive element; solid; and 252.” Next is “100; fermium; F m; radioactive element; solid; and 257.” Next is “101; mendelevium; M d; radioactive element; solid; and 258.” Next is “102; nobelium; N o; radioactive element; solid; and 259.” The last in this special row is “103; lawrencium; L r; radioactive element; solid; and 262.” Continuing in period 7, group 4 contains “104; rutherfordium; R f; transition and inner transition metal; solid; and 267.” Group 5 contains “105; dubnium; D b; transition and inner transition metal; solid; and 270.” Group 6 contains “106; seaborgium; S g; transition and inner transition metal; solid; and 271.” Group 7 contains “107; bohrium; B h; transition and inner transition metal; solid; and 270.” Group 8 contains “108; hassium; H s; transition and inner transition metal; solid; and 277.” Group 9 contains “109; meitnerium; M t; radioactive element; solid; and 276.” Group 10 contains “110; darmstadtium; D s; radioactive element; solid; and 281.” Group 11 contains “111; roentgenium; R g; radioactive element; solid; and 282.” Group 12 contains “112; copernicium; C n; radioactive element; liquid; and 285.” Group 13 contains “113; ununtrium; U u t; radioactive element; solid; and 285.” Group 14 contains “114; flerovium; F l; radioactive element; solid; and 289.” Group 15 contains “115; ununpentium; U u p; radioactive element; solid; and 288.” Group 16 contains “116; livermorium; L v; radioactive element; solid; and 293.” Group 17 contains “117; ununseptium; U u s; radioactive; solid; and 294.” Group 18 contains “118; ununoctium; U u o; radioactive element; solid; and 294.”

The location of the representative metals is shown in the periodic table. Nonmetals are shown in green, metalloids in purple, and the transition metals and inner transition metals in blue.

Most of the representative metals do not occur naturally in an uncombined state because they readily react with water and oxygen in the air. However, it is possible to isolate elemental beryllium, magnesium, zinc, cadmium, mercury, aluminum, tin, and lead from their naturally occurring minerals and use them because they react very slowly with air.

Part of the reason why these elements react slowly is that these elements react with air to form a protective coating. The formation of this protective coating is passivation. The coating is a nonreactive film of oxide or some other compound. Elemental magnesium, aluminum, zinc, and tin are important in the fabrication of many familiar items, including wire, cookware, foil, and many household and personal objects. Although beryllium, cadmium, mercury, and lead are readily available, there are limitations in their use because of their toxicity.

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This is a lesson from the tutorial, Metals, Metalloids, and Nonmetals and you are encouraged to log in or register, so that you can track your progress.

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