oxidation state of the atoms of the periodic system

Oxidation numbers of atoms

There is a clear relationship between oxidation number (or oxidation state) atom and its position in the periodic table. Oxidation number of atoms in covalent compounds atoms is defined as an imaginary charge which will be owned when the electrons are shared equally divided between bonded atoms (atoms that are bonded together) or handed over all the atoms are more strongly appeal (if different atoms bonded ).

(1) GROUP KEY ELEMENTS

For the main group elements, oxidation in many cases is the number of electrons will be released or received to achieve the full electron configuration, ns2np6 (except for the first period) or an electron configuration nd10.

It is clear for elements of low period which is a member group 1, 2 and 13-18. For larger periods, the trend has oxidation associated with the configuration of the electrons with the electrons retained ns and np electrons are removed. For example, lead tin Sn and Pb, both class 14, has a +2 oxidation state by removing electrons NP2 but retain ns2 electrons, in addition to the oxidation state +4. The same reasoning can be used to the fact that phosphorus P and bismuth Bi, two groups of 15 with electron configuration ns2np3, has an oxidation state of +3 and +5.

Generally, the importance of ns2 electron oxidation to be maintained will become increasingly important for a greater period. For nitrogen and phosphorus compounds, oxidation number +5 dominant, while the dominant bismuth is +3 and +5 oxidation state rather rare.

Metallic elements and semilogam (Si silicon or germanium Ge) rarely has a negative oxidation value, but for non-metals are common phenomena. In nitrogen and phosphorus hydride, NH3 and PH3, oxidation of N and P are-3. The higher period elements, the element will lose these properties and bismuth Bi does not have a negative oxidation. Among the group 16 elements, oxidation-2 dominant as in the case of oxygen O. This trend will again decline to elements in higher periods. Suppose oxygen only has a negative oxidation number, but it's had such a positive oxidation state +4 and +6 are also significant.

(2) ELEMENTS OF TRANSITION

Although the transition elements have multiple oxidation states, regularity can be recognized. Highest oxidation number of atoms that have five electrons the number of d orbitals associated with the current state of all the d electrons (electrons than s) removed. So, in the case of scandium with electron configuration (n-1) d1ns2, oxidation number 3. Manganese configuration with (n-1) d5ns2, will berbilangan maximum oxidation +7.

If the amount exceeds 5 d electrons, the situation changed. For iron Fe with electron configuration (n-1) d6ns2, primarily oxidation +2 and +3. Very rare oxidation state +6. Highest oxidation number a number of important transition metals such as cobalt Co, Ni Nickel, copper and zinc Zn Cu lower oxidation states of atoms lose all electrons (n-1) d and ns it. Among the elements that are in the same group, the higher the oxidation state of the elements essential for a greater period.

Concept of Oxidation Numbers

Understanding Oxidation Numbers:

Electric charge as if possessed by the elements in a compound or ion.

OXIDATION NUMBERS PRICE

1. Oxidation Bialngan free element = 0

2. Oxygen

In compounds Oxidation Numbers = -2

except

a. In peroxide, Oxidation Numbers = -1

b. In superoxide, Numbers Oxide = -1 / 2

c. In of2, Oxidation Numbers = +2

3. Hydrogen

In compounds, Oxidation Numbers = +1

Except in hybrid = -1

4. The elements of Group IA

In compounds, Oxidation Numbers = +2

5. The elements of Group IIA

In compounds, Oxidation Numbers = +2

6. Oxidation Numbers  molecule = 0

7. Oxidation Numbers  ion = charge on the ion

8. Halogens

F: 0, -1

Cl: 0, -1, +1, +3, +5, +7

Br: 0, -1, +1, +5, +7

I: 0, -1, +1, +5, +7