Star InactiveStar InactiveStar InactiveStar InactiveStar Inactive

Specific distribution of electrons in atomic orbitals of atoms or ions.

Latest Articles

  • Chemical Safety

    People use chemicals every day for a wide array of purposes, which can include work and house hold duties. Many of us fail to realize that we are actually handling potentially deadly chemicals when we simply clean the bathroom or wash the car. This brings to mind the reason why chemical safety is...

  • The most expensive metal in the world

    Do you think the most expensive metal is gold? No! On earth there are more valuable metals. But we need to divide the value of metals that occur in nature, and metals - isotopes, which are obtained in special laboratories. Let’s look at natural metals first.

  • Features of the Scanning Tunneling Microscope

    The scanning tunneling microscope (STM) invented by Heinrich Rohrer and Gerd Binnig in the 1980s still manages to do a great job today and competes with more advanced microscope types. The scanning tunneling microscope is used for studying the surface atoms that are found on various materials. The...

  • Interesting facts about metals

    Metals have been used by people since ancient times. All the time the process of obtaining them was improved, useful alloys of various metals appeared. Let’s look at interesting facts about metals.

  • Protein Design: Automated protein discovery and synthesis

    In this paper I describe (theoretically) the method(s) of automated protein discovery and synthesis.

Most Popular

Nonpolar Bond

Covalent bond in which electron density is symmetrically distributed.

Basic Anhydride

The oxide of a metal that reacts with water to form a base.

Single Bond

Covalent bond resulting from the sharing of two electrons (one pair) between two atoms.


A rare trivalent metallic element, found in gadolinite and other minerals. Symbol: Y, at. wt.: 88.905, at. no.: 39, sp. gr.: 4.47. Cf."rare-earth element."

Yttrium has a silver-metallic luster and is relatively stable in air unless finely divided. Turnings of the metal, however, ignite in air if their temperature exceeds 400oC. Yttrium oxide is one of the most important compounds of yttrium and accounts for the largest use. It is widely used in making YVO4 europium, and Y2O3 europium phosphors to give the red color in color television tubes.


A heavy, colorless, chemically inactive, monatomic gaseous element used for filling radio, television, and luminescent tubes. Symbol: Xe, at. wt.: 131.30, at. no.: 54.

Coefficient of expansion

The ratio of the change in length or volumen of a body to the original lengthor volume for a unit change in temperature.


A substance added to react with the charge, or a product of its reduction, in metallurgy, usually added to lower a melting point.

Oxidation Numbers

Arbitrary numbers that can be used as mechanical aids in writing formulas and balancing equations, for single- atom ions they correspond to the charge on the ion, more electronegative atoms are assigned negative oxidation numbers (also called Oxidation states).


Refers to an optically active substance that rotates the plane of plane polarized light clockwise, also called dextro.

Antibonding Orbital

A molecular orbital higher in energy than any of the atomic orbitals from which it is derived, lends instability to a molecule or ion when populated with electrons, denoted with a star (*) superscript or symbol.