States of matter
From Simple English Wikipedia, the free encyclopedia
There are three common states of matter (or physical forms of matter) on earth: solid, liquid, and gas.
In a solid the positions of atoms are fixed relative to each other over long time. That is due to the cohesion between molecules. This cohesion is provided by metallic, covalent or ionic bonds. But there are many types of intermolecular bonds in the different materials classes: ceramics, metals, semiconductors or polymers, and each material or compound may be different. Only solids can sustain a stress without continually deforming, that means that they can be resistant to deformation.
When a solid becomes a liquid, this is called melting. When a solid becomes a gas, this is called sublimation.
In a liquid, ionic interactions between molecules are strong enough to keep molecules in contact, but not strong enough to fix a particular structure, and the molecules can continually move with respect to each other.
In a gas, the chemical bonds are not strong enough to hold atoms or molecules together, and thus a gas is a collection of independent, unbonded molecules which interact mainly by collision.
The most common state of matter in the universe is plasma. Less familiar phases include: quark-gluon plasma; Bose-Einstein condensates and fermionic condensates; strange matter; superfluids and supersolids, and possibly string-net liquids.
[edit] External links
- 2005-06-22, MIT News: MIT physicists create new form of matter Citat: "... They have become the first to create a new type of matter, a gas of atoms that shows high-temperature superfluidity."
- 2003-10-10, Science Daily: Metallic Phase For Bosons Implies New State Of Matter
- 2004-01-15, ScienceDaily: Probable Discovery Of A New, Supersolid, Phase Of Matter Citat: "...We apparently have observed, for the first time, a solid material with the characteristics of a superfluid...but because all its particles are in the identical quantum state, it remains a solid even though its component particles are continually flowing..."
- 2004-01-29, ScienceDaily: NIST/University Of Colorado Scientists Create New Form Of Matter: A Fermionic Condensate
