Question

what is oxidation number. can u explain me in detalic form

Answer 1

It's important to know if an atom loses or gains electrons when combining with other atoms to form compounds. How do we keep track of the electrons lost or gained by an atom? We do this by looking at an atom's oxidation number.

An oxidation number is a number that is assigned to an atom in a substance. The oxidation number could be positive, negative, or zero, and it indicates if electrons are lost or gained. In other words, the oxidation number is a number that helps us keep track of electrons in an atom.

Here, the oxidation number of calcium is +2 and the oxidation number of oxygen is -2.

If the oxidation number is positive, then this means that the atom loses electrons, and if it is negative, it means the atom gains electrons. If it is zero, then the atom neither gains nor loses electrons.

Calcium has a +2 charge, which means it lost two electrons. Oxygen has a -2 charge, which means it gained two electrons.

If an atom loses electrons, its oxidation number is positive, so we can say that this atom undergoes oxidation. If an atom gains electrons, its oxidation number is negative, so we can say that the atom undergoes reduction.

You can remember this by thinking of the phrase OIL RIG: Oxidation Is Loss (of electrons); Reduction Is Gain 

Answer 2

a number assigned to an element in chemical combination which represents the number of electrons lost by an atom of that element in the compound.