Microsoft Word - WaterChemistry

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Cerium, left, Dysprosium, right.

Examples of allotropes include:
Non-metals

Element Allotropes

Carbon

 Diamond - an extremely hard, transparent crystal, with the carbon

atoms arranged in a tetrahedral lattice. A poor electrical conductor.

An excellent thermal conductor.

 Lonsdaleite - also called hexagonal diamond.

 Graphite - a soft, black, flaky solid, a moderate electrical

conductor. The C atoms are bonded in flat hexagonal lattices

(graphene), which are then layered in sheets.

 Linear acetylenic carbon (Carbyne)

 Amorphous carbon

 Fullerenes, including Buckminsterfullerene, aka "buckyballs", such

as C 60.

 Carbon nanotubes - allotropes of carbon with a cylindrical

nanostructure.

Phosphorus:

 White phosphorus - crystalline solid P 4

 Red phosphorus - polymeric solid

 Scarlet phosphorus

 Violet phosphorus

 Black phosphorus - semiconductor, analogous to graphite

 Diphosphorus

Oxygen:

 dioxygen, O 2 - colorless (faint blue)

 Ozone, O 3 - blue

 Tetraoxygen, O 4 - metastable

 Octaoxygen, O 8 - red

Sulfur:  Sulfur has a large number of allotropes, second only to carbon

Selenium:

 "Red selenium," cyclo-Se 8

 Gray selenium, polymeric Se

 Black selenium