An atom is oxidized when its oxidation number increases during a chemical reaction; it's also known as the reducing agent.
Understanding Oxidation
Oxidation, at its core, involves a change in the oxidation state of an atom. Let's break it down:
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Oxidation Number: This represents the hypothetical charge an atom would have if all bonds were completely ionic.
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Oxidation: An increase in the oxidation number signifies oxidation. This typically means the atom has lost electrons. According to the reference, an atom is oxidized if its oxidation number increases, the reducing agent.
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Reducing Agent: The atom that causes another atom to be reduced (i.e., gain electrons) is itself oxidized. Therefore, the atom being oxidized is the reducing agent.
Example:
Consider a simple reaction:
$Zn(s) + Cu^{2+}(aq) \rightarrow Zn^{2+}(aq) + Cu(s)$
Here:
- Zinc (Zn) goes from an oxidation state of 0 to +2. Its oxidation number increases, so it is oxidized.
- Copper (Cu) goes from an oxidation state of +2 to 0. Its oxidation number decreases, so it is reduced.
In this example, zinc is the atom that is oxidized, acting as the reducing agent.
