In 1799, Joseph Louis Proust was the first to recognize that chemical compounds may have a definite, constant composition. Proust formally stated a law of constant proportions. This law raised the possibility that elements might have certain...

Valence refers to a number assigned to elements that reflects their ability to react with other elements and the type of reactions the element will undergo. The term valence is derived from the Latin word for strength and can reflect an element's...

In chemistry, valence, also known as valency or valency number, is a measure of the number of chemical bonds formed by the atoms of a given element. Over the last century, the concept of valence evolved into a range of approaches for describing the...

I David Brown Oxford: Oxford University Press, 2003 'There are rather too many models of chemical bonding in existence,' says the author, as he introduces yet another model. How does this apparent paradox arise, and how is it to be resolved?...

NEW YORK--Valence Technology Inc., Henderson, Nev., plans no less than a revolution in rechargeable batteries by introducing a power source based on phosphate. Within a few months, Valence will identify an Asian original equipment manufacturer as its first partner for mass production,...

Take-Two Interactive Software Inc., the troubled video game publisher behind the "Grand Theft Auto" series, said Monday it is looking into options that could include a sale of the company.Take-Two, which is facing an attempt by a shareholder group to replace its board and possibly...

The battle between conservative Nicolas Sarkozy and Socialist Segolene Royal heated up Tuesday with both candidates in France's presidential runoff trying to woo voters in the political center who hold the ticket to victory.Centrist candidate Francois Bayrou is no longer in the running, but his...