Metalloid
Metalloids are a group of chemical elements with properties that are intermediate between those of metals and nonmetals.
term used in chemistry when classifying the chemical elements. On the basis of their general physical and chemical properties, nearly every element in the periodic table can be termed either a metal or a nonmetal. A few elements with intermediate properties are, however, referred to as metalloids. (In Greek metallon = metal and eidos = sort)
There is no rigorous definition of the term, but the following properties are usually considered characteristic of metalloids:
- metalloids often form amphoteric oxides.
- metalloids often behave as semiconductors (B,Si,Ge) to semimetals (eg. Sb).
The following elements are generally considered metalloids:[1]
Some allotropes of elements exhibit more pronounced metal, metalloid or non-metal behavior than others. For example, for the element carbon, its diamond allotrope is clearly non-metallic, but the graphite allotrope displays limited electric conductivity more characteristic of a metalloid. Phosphorus, tin, selenium and bismuth also have allotropes that display borderline behavior.
Position in the Periodic Table
In the standard layout of the periodic table, metalloids occur along a diagonal line through the p block, from boron to polonium. Elements to the upper right of this line display increasing nonmetallic behavior; elements to the lower left display increasing metallic behavior. This line is called the "stair-step" or "staircase." The poor metals are to the left and down, and the nonmetals are to the right and up.
| 13 | 14 | 15 | 16 | 17 |
|---|---|---|---|---|
| B Boron |
C Carbon |
N Nitrogen |
O Oxygen |
F Fluorine |
| Al Aluminium |
Si Silicon |
P Phosphorus |
S Sulfur |
Cl Chlorine |
| Ga Gallium |
Ge Germanium |
As Arsenic |
Se Selenium |
Br Bromine |
| In Indium |
Sn Tin |
Sb Antimony |
Te Tellurium |
I Iodine |
| Tl Thallium |
Pb Lead |
Bi Bismuth |
Po Polonium |
At Astatine |
Metalloid or semiconductor?
The concepts of metalloid and semiconductor should not be confused with each other. The term metalloid refers to the properties of certain elements in relation to the periodic table. The term semiconductor refers to the physical properties of materials (including alloys and compounds). There is only partial overlap between the two.
See also
Notes
ReferencesISBN links support NWE through referral fees
- Brown Jr., Theodore L., H. Eugene LeMay, Bruce Edward Bursten, and Julia R. Burdge. 2002. Chemistry: The Central Science. 9th ed. Upper Saddle River, NJ: Prentice Hall. ISBN 0130669970.
- Chang, Raymond. 2006. Chemistry. 9th ed. New York, NY: McGraw-Hill Science/Engineering/Math. ISBN 0073221031.
- Cotton, F. Albert, and Geoffrey Wilkinson. 1980. Advanced Inorganic Chemistry. 4th ed. New York, NY: Wiley. ISBN 0-471-02775-8.
- Greenwood, N.N., and A. Earnshaw. 1998. Chemistry of the Elements. 2nd ed. Oxford, U.K.; Burlington, MA: Butterworth-Heinemann, Elsevier Science. ISBN 0750633654. Online version available here. Retrieved July 23, 2008.
External links
| Standard table | Vertical table | Table with names | Names and atomic masses (large) | Names and atomic masses (small) | Names and atomic masses (text only) | Inline F-block | Elements to 218 | Electron configurations | Metals and non metals | Table by blocks | List of elements by name |
| Groups: 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 - 10 - 11 - 12 - 13 - 14 - 15 - 16 - 17 - 18 |
| Periods: 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 |
| Series: Alkalis - Alkaline earths - Lanthanides - Actinides - Transition metals - Poor metals - Metalloids - Nonmetals - Halogens - Noble gases |
| Blocks: s-block - p-block - d-block - f-block - g-block |
| Periodic table | |||||||||||||||||||||||||||||||||||||||||
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| H | He | ||||||||||||||||||||||||||||||||||||||||
| Li | Be | B | C | N | O | F | Ne | ||||||||||||||||||||||||||||||||||
| Na | Mg | Al | Si | P | S | Cl | Ar | ||||||||||||||||||||||||||||||||||
| K | Ca | Sc | Ti | V | Cr | Mn | Fe | Co | Ni | Cu | Zn | Ga | Ge | As | Se | Br | Kr | ||||||||||||||||||||||||
| Rb | Sr | Y | Zr | Nb | Mo | Tc | Ru | Rh | Pd | Ag | Cd | In | Sn | Sb | Te | I | Xe | ||||||||||||||||||||||||
| Cs | Ba | La | Ce | Pr | Nd | Pm | Sm | Eu | Gd | Tb | Dy | Ho | Er | Tm | Yb | Lu | Hf | Ta | W | Re | Os | Ir | Pt | Au | Hg | Tl | Pb | Bi | Po | At | Rn | ||||||||||
| Fr | Ra | Ac | Th | Pa | U | Np | Pu | Am | Cm | Bk | Cf | Es | Fm | Md | No | Lr | Rf | Db | Sg | Bh | Hs | Mt | Ds | Rg | Uub | Uut | Uuq | Uup | Uuh | Uus | Uuo | ||||||||||
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