Final answer:
The oxidation number is a positive or negative number that symbolizes the hypothetical charge an atom would have in a molecule or ion. It's used to determine the degree of oxidation or reduction an atom undergoes and to follow electron transfer in reactions.
Step-by-step explanation:
The oxidation number is a concept used in chemistry that represents the charge an atom would have if electrons were distributed according to certain rules. It is a positive or negative number that gives us an idea of the degree of oxidation or reduction an atom has undergone during a reaction. The process of assigning oxidation numbers makes it easier to track electron transfer in oxidation-reduction processes, which are reactions where the exchange of electrons is the main event.
Here are a few general rules for assigning oxidation numbers:
An atom in its elemental form has an oxidation number of zero.
- The oxidation number of a monatomic ion is the same as its charge.
- Common nonmetals like hydrogen, oxygen, and the halogens have specific oxidation numbers based on their chemical surroundings, such as hydrogen being +1 with nonmetals and -1 with metals, or oxygen normally being -2, except in peroxides and superoxides.