So why do so many life-forms breathe oxygen? There are probably thousands of kinds of metabolisms, or chemical processes that maintain life, said Donald Canfield, a geobiologist at the University of ...

Electronegativity is a derived quantity, so it is not directly measurable. It is relative to hydrogen which was assigned a value of 2.20 on the Pauling scale. In an oxygen (O2) molecule, both atoms ...

electrons accumulate around the more electronegative element, increasing the availability of electrons for the transition metal and preventing oxidation of oxygen. Conversely, when there are ...

Sulfur is also less electronegative than oxygen, permitting it to more readily adopt a positive charge, which is used by a number of enzyme cofactors. S-adenosylmethionine (SAM or AdoMet), which ...