The oxidation number of copper in Cu
is
The Correct Answer and Explanation is:
The oxidation number of copper in Cu (elemental copper) is 0.
This is because in its elemental form, copper exists as Cu alone, which is not combined with any other elements. The oxidation number of an element in its pure, uncombined state is always zero.
To understand this in more detail, we need to look at how oxidation numbers are assigned. Oxidation numbers are used to represent the number of electrons that an atom gains or loses when forming a compound. These numbers help track the flow of electrons in redox reactions, where one substance is oxidized (loses electrons) and another is reduced (gains electrons).
For example, in compounds like CuSO₄ (copper(II) sulfate), copper has an oxidation number of +2 because it loses two electrons when it combines with sulfate ions. But in elemental copper (Cu), it has not lost or gained any electrons, so its oxidation number is 0.
To summarize:
- In Cu, which is copper in its pure elemental form, the oxidation number is 0.
- This is true for all elements when they are not part of a compound, such as O₂, N₂, and H₂, where each element has an oxidation number of 0 in their elemental state.
This concept of oxidation states is a fundamental part of understanding chemical reactions, especially redox reactions, where electron transfer is key.
