NURUL AINA PUTERI
113194033
PENDIDIKAN KIMIA INTERNASIONAL 2011
UNIVERSITAS NEGERI SURABAYA
METALLOIDS
113194033
PENDIDIKAN KIMIA INTERNASIONAL 2011
UNIVERSITAS NEGERI SURABAYA
METALLOIDSA.
D Definition
D Definition
Some of the elements contiguous to the line are intermediate in character and are called metalloids. (J. Rex Goates, J. Bevan Ott, & Eliot A. Butler, 1981: 13)
The elements can be roughly divided into three groups: metals, nonmetals, and metalloids (sometimes called semimetals)
While there is often no sharp line between metal and nonmetal, those elements which are classed as metallic always exhibit a positive valence, whereas nonmetals usually show a negative valence. Elements which exhibit properties of both metals and nonmetals are termed metalloids. (G. Brooks King, William E. Caldwell, & Max B. Williams, 1977: 86)
The borderline elements or metalloids. Borderline elements, or metalloid, are elements which to some extent exhibit both metallic and nonmetallic properties; they usually act as electron donors with non-metals, and as electron acceptors with metals. Chemist do not agree as to exactly which elements should be included in this class, but they do agree that such elements lie close to the zigzag line in the periodic table. The names of some of these elements are boron, B, silicon, Si, germanium, Ge, and tellurium, Te. They are all solids at room temperature, somewhat brittle, and rather poor conductors of heat and electricity. The metalloid oxides which react with water yield solutions that are either weakly acidic or weakly basic. (J. H. Wood, C. W. Keenan, W. E. Bull, & N. S. Bowman, 1966: 75-76)
There are several elements, called metalloids that are neither distinctly metallic nor distinctly nonmetallic in their chemical behavior. Under some conditions, these elements have properties that are characteristic of metals. Under conditions, their properties are distinctly nonmetallic. Metalloids have certain unusual properties that make them useful ass semiconductors in transistors. Examples of metalloids are boron, germanium, silicon, and antimony. (Henry Dorin, 1987: 279-280)
Unsur-unsur yang dibahas sejauh ini berada pada batas antara padatan kovalen dan padatan diantara logam dan kovalen dan dinamakan metalloid. Misalnya, antimony mempunyai kilap logam tetapi mempunyai sifat penghantaran listrik dan kalor yang agak buruk. Silicon dan germanium adalah semikonduktor, dengan konduktivitas listrik yang jauh lebih rendah daripada logam tetapi masih jelas lebih tinggi daripada isolator sejati seperti intan. (David W. Oxtoby, N.P. Gillis, & Norman H. Nachtarieb†, 2003: 181)
B. Characteristic/Properties
Metaloid mempunyai sifat-sifat yang berada diantara logam dan nonlogam. Gambar 2.9 menunjukkan bahwa sebagian besar unsure yang telah dikenal berupa logam; hanya tujuh belas unsur yang merupakan nonlogam, dan delapan unsure yang merupakan metalloid. (Raymond Chang, 2005: 38)
None of the metalloids is so commonly encountered in the elementary state, and we cannot fall back on everyday experience for recognition of the intermediate properties characteristic of metalloids. A brief statement of the properties of arsenic should help you to see why it is classed as a metalloid. The stable form of elementary arsenic is gray in color, has bright luster, is very brittle, conducts heat, but is a poor conductor of electricity. (J. Rex Goates, J. Bevan Ott, & Eliot A. Butler, 1981: 16)
Only seven elements are metalloids, so-named because their properties are intermediate between those of metals and nonetals. Boron, silicon, and arsenic are examples. Pure silicon has a lustrous or shiny surface, like a metal, but is brittle, like a nonmetal, its electrical conductivity lies between metals on the left and nonmetals on the right side of the periodic table. (John McMurry, Mary E. Castellion, & David S. Ballatine, 2007: 10)
Metals and nonmetals are often separated by a stairstep diagonal line, and several elements near this line are often called metalloids (green). Metalloids are elements that look like metals and in some ways behave like metals but also have some nonmetallic properties. (Ralph H. Petrucci, William S. Harwood, F. Geoffrey Hering, & Jeffry D. Madura, 2007: 344)
Table 7.1 Specific Heats of Several Solid Elements, J g-1 ˚C-1. Metalloids: Tellurium 0.202; Arsenic 0.329. (Ralph H. Petrucci, William S. Harwood, F. Geoffrey Hering, & Jeffry D. Madura, 2007: 231)
The metalloids are elements with borderline behavior. They have some properties characteristic of metals and other properties characteristic of nonmetals. Examples of metalloids are boron, silicon, arsenic, and tellurium. (Henry Dorin, 1987: 324)
C. Classification/Elements of Metalloids
Several elements (boron, silicon, germanium, arsenic, antimony, tellurium, and polonium) are classified as metalloids and have properties that are intermediate between those of metals and those nonmetals. The intermediate position of these elements is shown in table 3.5. Certain metalloids, such us boron, silicon and germanium, are the raw materials for the semiconductor devices that make the electronics industry possible. (Morris Hein & Susan Arena, 2011: 50)
Germanium, sometimes referred to as a metalloid (or semi-metal), exhibits semiconductor properties, is mostly nonmetallic in its chemical behavior but is sometimes classified as a metalloid. (Ralph H. Petrucci, William S. Harwood, F. Geoffrey Hering, & Jeffry D. Madura, 2007: 895)
D. Location/Position on Periodic Table
Seven of the elements adjacent to the zigzag boundary between metals and nonmetals are metalloids. (John McMurry, Mary E. Castellion, & David S. Ballatine, 2007: 57)
Two other highlighted categories in Figure 2-15 are a special group of nonmetals known as the noble gases (pink), and a small group of elements, often called metalloids (green), that have some metallic and some nonmetallic properties. (Ralph H. Petrucci, William S. Harwood, F. Geoffrey Hering, & Jeffry D. Madura, 2007: 51)
Those elements (except hydrogen) on the left-hand side of the zigzag line running from boron (B) to astatine (At) are metals, those elements to the right of the line are nonmetals, and those elements abutting the line are metalloids. (John McMurry, Mary E. Castellion, & David S. Ballatine, 2007: 55)
Elements which border on the shaded area in Fig. 17-1 often exhibit one or more of the properties listed above. These elements are referred to as metalloids, to indicate that their properties are intermediate between those of metallic and non-metallic elements. (Theodore L. Brown, 1968: 403)
DAFTAR PUSTAKA
1. McMurry, John, Castellion, Mary E., & Ballatine, David S. (2007). Fundamentals of General, Organic and Biological Chemistry. United States of America: Pearson Education, Inc.
2. Petrucci, Ralph H., Harwood, William S., Hering, F. Geoffrey, & Madura, Jeffry D. (2007). General Chemistry Principles & Modern Applications. United States of America: Pearson Education, Inc.
3. Oxtoby, David W., Gillis, N. P., & Nachtrieb, Norman H. (2003). Prinsip-prinsip Kimia Modern/Ed. 4/JL. 2. Jakarta: Penerbit Erlangga.
4. Hein, Morris & Arena, Susan. (2011). Introduction to Chemistry. Asia: Wiley.
5. Dorin, Henry. (1987). Chemistry The Study of Matter. United States of America: Allyn and Bacon, Inc.
6. Goates, J. Rex, Ott, J. Bevan, & Butler, Eliot A. (1981). General Chemistry Theory and Description. United States of America: Harcourt Brace Jovanovich, Inc.
7. King, G. Brooks, Caldwell, William E., & Williams, Max B. (1997). College Chemistry Seventh Editions. New York: Litton Educational Publishing, Inc.
8. Wood, J. H., Keenan, C. W., & Bowman, N. S. (1966). Fundamentals of College Chemistry. New York: Harpen & Row, Publishers, Inc.
9. Brown, Theodore L. (1968). General Chemistry Second Edition. Ohio: Charles E. Merrill Publishing Company.
10. Chang, Raymond. (2005). Kimia Dasar Konsep-konsep Inti Edisi Ketiga. Jakarta: Penerbit Erlangga.
