allotrope

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allotrope

any of two or more physical forms in which an element can exist

allotrope

[′a·lə‚trōp]

(chemistry)

A form of an element showing allotropy.

allotrope

A chemical element that can take on different forms based on the structure of, or the number of atoms in, the molecule. The most common example is carbon. If carbon atoms are bonded in a lattice of four triangular surfaces (tetrahedral), it is a diamond. If the atoms are bonded in sheets of six-sided (hexagonal) lattice, it is graphite. See isotope.

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References in periodicals archive ?

X-ray photoemission study of orthorhombic selenium; a new allotrope of crystalline selenium.

Effect of oral supplementation of biogenic selenium nanoparticles on white blood cell profile of BALB/c mice and mice exposed to X-ray radiation

Similarly, a comparison of the Raman spectra of two carbon allotropes, diamond and graphite, easily distinguishes the two materials even though both are composed entirely of C-C bonds.

Characterizing carbon nanomaterials: Raman spectroscopy can detect small changes in the structural morphology of carbon nanomaterials, making it an ideal solution for material sciences

EPA considers substances to have different molecular identities when they have different molecular formulas; have the same molecular formulas, but have different atom connectivities; have the same molecular formulas and atom connectivities, but have different spatial arrangements of atoms; have the same type of atoms, but have different crystal lattices, (26) are different allotropes (27) of the same element, or have different isotopes (28) of the same elements.

Nanotechnology and the dilemmas facing business and government

As a chemical term, allotropic means "having different physical properties, though unchanged in substance" (OED), such as diamonds and coal both being allotropes of carbon.

Reading Miller's "Numinous Cock": heterosexist presumption and queerings of the censored text

They identified and measured subatomic particles and radiation, rejected "plum pudding" atoms, imagined "liquid-drop" nuclei, quantified isotopes and allotropes, and finally, in the late 1930s, came to understand that splitting atoms to release enormous energy was not only theoretically possible, but technically feasible.

Jeremy Bernstein. Nuclear Weapons: What You Need to Know

Curiously, ironically, it is deeply bound up with that unmodulated craving for perfection that often goes under the name of idealism but really is one of the more destructive allotropes of sentimentality.

Notes & comments: September 2005

One can also probe physical properties, including molecular orientation, degree of crystallinity, polymorphs or allotropes, crystal and domain size, crystal defects, and stress/strain.

Raman spectroscopy in coatings research and analysis: Part I. Basic principles

The ropes might well be the allotropes of puppet strings, even if the dependent manikins in Two Standing Nudes and The Strange Man are stringless.

Jared French's iconic enigmas

But allotropy is a property special to (dependent on) allotropes and should appear only under allotropes.

Faceted classification and logical division in information retrieval

Carbon in all its many forms--diamonds, graphite, fullerenes, coal, and other allotropes, including solid, liquid, gaseous, and plasma forms--may join silicon as a key and virtually inexhaustible resource.

The Brave New World of Meta-Materials

As a space-saving measure the figural complex in question will sometimes be referred to as a tropeme, and the three individual figures as allotropes without, however, any attempt being made to press exaggerated claims for conceptual originality or universal applicability.

The post-soviet apocalypse and its spatial allotropes

Diamond and graphite, the only other known allotropes of carbon, require temperatures on the order of 3000 [degrees] C (5400 [degrees] F) to evaporate.