The oxidation state or oxidation number is defined as the sum of negative and positive Charge is a word with many different meanings. Science In science, the concept of charge is derived from the observation of conserved quantum numbers. Various charge_like quantum numbers have been introduced by theories of particle physics, e.g. electric charge for electromagnetic interaction, magnetic charge (currently purely hypothetic), colour charge... charges in an Properties For alternative meanings see atom (disambiguation). An atom ( Greek άτομον) is a microscopic structure found in all ordinary matter around us. Atoms are composed of 3 types of subatomic particles: electrons, which have a negative charge; protons, which have a positive charge; and neutrons... atom, which indirectly indicates the number of Properties The electron (also called negatron, commonly represented as e−) is a subatomic particle. In an atom the electrons surround the nucleus of protons and neutrons in an electron configuration. The word electron is a transliteration of the Greek word ηλεκτρον, which... electrons it has accepted or donated. The oxidation number is a convenient conceptual approximation when working with complex electrochemical reactions that eases the tracking of electrons and helps verify that they have been conserved. This is especially useful whilst expressing complex A half reaction is either the oxidation or reduction reaction component of a redox reaction. A half reaction is obtained by considering the change in oxidation states of individual substances involved in the redox reaction. Consider the reaction below: (1) Cl2 + 2Fe2+ -> 2Cl- + 2Fe3+ The two elements involved, iron... half-reaction equations involved in The most fundamental reactions in chemistry are the redox processes. The term redox process accounts for all processes in which atoms have their oxidation number (oxidation state) changed. This can be a simple redox process, such as the combustion of carbon by oxygen to yield carbon dioxide, it could be... oxidation/ Reduction or reducing has several meanings: In mathematics, reduction is the process of manipulating a series of equations or matrices into a desired simpler format. In computational complexity theory, reduction is the transformation of an instance of one problem into an equivalent instance of another. In cooking, reduction is the... reduction reactions.

Atoms are defined as having an oxidation number of zero, meaning that they are electrically neutral. The positive For alternative meanings see proton (disambiguation). Properties In physics, the proton (Greek proton = first) is a subatomic particle with a positive fundamental electric charge of 1.6 × 10−19 coulomb and a mass of 938 MeV/c2 (1.6726231 × 10−27 kg, or about 1800 times the mass... protons in the The nucleus (atomic nucleus) is the center of an atom. It is composed of one or more protons and one or more neutrons as well, except for the nucleus consisting of a single proton. The number of protons in an atoms nucleus is called the atomic number, and determines... nucleus balance the negative Properties The electron (also called negatron, commonly represented as e−) is a subatomic particle. In an atom the electrons surround the nucleus of protons and neutrons in an electron configuration. The word electron is a transliteration of the Greek word ηλεκτρον, which... electron cloud surrounding it, there being equal numbers of both. If an atom donates an electron it has more protons than electrons and becomes positive. This This article is about the electrically charged molecule. For other uses of this word, see ion (disambiguation). An ion is an atom or group of atoms with a net electric charge. A negatively charged ion, which has gained one or more electrons, is known as an anion, for it is... ion is said to have an oxidation number of +1. Conversely if an atom accepts an electron it becomes negatively charged, gaining an oxidation number of -1. In summary, if an atom or ion donates an electron in a reaction its oxidation state is increased by one, if an element accepts an electron its oxidation state is decreased by one.

Oxidation numbers are denoted in There are millions of possible objects that can be described in science, too many to create common names for every one. As a response, a number of systems of systematic names have been created. These can be as simple as assigning a prefix and a number to each object (in... chemical names by bracketed Roman numerals placed immediately after the relevant element. For example, an iron ion, with an oxidation state of +3 is expressed as iron(III). Manganese with an oxidation state of +7 present in manganese oxide is given the name manganese(VII) oxide. The motive for placing oxidation numbers in names is only to distinguish between different compounds of the same elements. The actual charge (positive/negative) of the ion is not expressed because it is not necessary for this purpose.

In A chemical formula (also called molecular formula) is a concise way of expressing information about the atoms that constitute a particular chemical compound. It identifies each type of element by its chemical symbol and identifies the number of atoms of such element to be found in each discrete molecule of... chemical formulae, the oxidation number of ions is placed in superscript after the element's symbol. For example, oxygen(-II) is written as O^2-. Oxidation numbers of neutral numbers are not expressed. The following formula describes the element I₂ accepting two electrons to gain an oxidation number of -1.

I₂ + 2e^- → 2I^-

When dealing with oxidation-reduction or " The most fundamental reactions in chemistry are the redox processes. The term redox process accounts for all processes in which atoms have their oxidation number changed. This can be a simple redox process, such as the combustion of carbon by oxygen to yield carbon dioxide, it could be the reduction... redox" reactions, the following rules define oxidation number:

• The atom with the greater Electronegativity is a measure of the attraction that an atom has for the bonding pair of electrons in a covalent bond. Two scales of electronegativity are in common use: the Pauling scale (proposed in 1932) and the Mulliken scale (proposed in 1934). There is also a Allred-Rochow scale. Pauling... electronegativity of dissimilar atoms sharing an electron is counted as receiving the electron.
• Identical atoms sharing an electron are each credited with one/half of the electron.

Sometimes it is not immediately obvious what the oxidation number of ions in a formula are from its molecular formula alone. For example, given Cr(OH)₃, no oxidation numbers are present yet it is clear that ionic bonding is occurring.

There are a number of rules that can be used in determining the oxidation number of a In science, a molecule is the smallest particle of a pure chemical substance that still retains its chemical composition and properties. A molecule consists of multiple atoms joined by shared pairs of electrons in a covalent bond. It may consist of atoms of the same chemical element, as with oxygen... molecule or ion:

1. The oxidation number of (neutral) atoms equal zero.
2. In neutral molecules, the sum of the oxidation numbers adds up to zero.
3. General Name, Symbol, Number Fluorine, F, 9 Series Halogens Group, Period, Block 17 (VIIA), 2 , p Density, Hardness 1.696 kg/m3, NA Appearance pale greenish-yellow gas Atomic properties Atomic weight 18.9984 g/mol Atomic radius (calc.) 50 (42) pm Covalent radius 71 pm van der Waals radius... Fluorine always has a -1 oxidation number within compounds.
4. General Name, Symbol, Number Oxygen, O, 8 Chemical series nonmetals Group, Period, Block 16 (VIA), 2, p Density, Hardness 1.429 kg/m3, NA Appearance colorless Atomic properties Atomic weight 15.9994 g/mol Atomic radius (calc.) 60 (48) pm Covalent radius 73 pm van der Waals radius 152 pm... Oxygen has an oxidation number of -2 in compounds, except (i) in the presence of fluorine, in which fluorine's oxidation number takes precedence; (ii) in oxygen-oxygen bonds, where one oxygen must neutralize the other's charge; (iii) in Peroxide has three distinct meanings: Colloquial meaning In common usage, peroxide is an aqueous solution of hydrogen peroxide (HOOH or H2O2) sold for use as a disinfectant or mild bleach. The usual peroxide of commerce is a dilute solution containing traces of stabilisers, and is sold in either brown glass... peroxide compounds, in which it takes an oxidation number of -1.
5. Group I ions have an oxidation number equal to +1 within compounds.
6. Group II ions have an oxidation number of +2 within compounds.
7. The halogens are a chemical series. They are the elements in Group 17 (old-style: VII or VIIA) of the periodic table: fluorine, chlorine, bromine, iodine, and astatine. The word comes from Greek roots meaning salt and creator. These elements are diatomic molecules in their natural form. They require one... Halogens, besides fluorine, generally have -1 oxidation numbers in compounds. This rule can be broken in the presence of oxygen or other halogens, where the oxidation numbers can be positive.
8. General Name, Symbol, Number Hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1 (IA), 1 , s Density, Hardness 0.0899 kg/m3, NA Appearance colorless Atomic properties Atomic weight 1.00794 amu Atomic radius (calc) 25 (53) pm Covalent radius 37 pm van der Waals radius 120 pm Electron... Hydrogen always has an oxidation number of +1 oxidation number in compounds, except in metal hydrides where instead it is -1.

With the example, Cr(OH)₃, oxygen has an oxidation number of -2 (no fluorine, O-O bonds or peroxide present), and hydrogen has a state of +1 (not a metal hydride). So, the triple Hydroxide is a functional group consisting of oxygen and hydrogen: -O−H It has a charge of 1-. The term hydroxyl group is used when the functional group -OH is counted as a substituent of an organic compound. Organic molecules containing a hydroxyl group are known as alcohols (CnH2n... hydroxide group has a charge of 3*(-2 + 1) = -3. As the compound is neutral, Cr has to have a charge of +3.

See also: Electrochemistry is the study of the electronic and electrical aspects of chemical reactions. The elements involved in an electrochemical reaction are characterized by the number of electrons each has. The oxidation state of an ion is the number of electrons it has accepted or donated compared to its neutral state... Electrochemistry, valency (chemistry)