* Oxidation is a chemical reaction where a substance loses electrons. This often involves the addition of oxygen.
Let's break down the other examples:
* Water evaporating: This is a physical change, where water changes state from liquid to gas. No chemical bonds are broken or formed.
* Sugar melting: This is also a physical change. The sugar molecules are simply changing their arrangement, not their chemical composition.
* Paper burning: This is a chemical reaction where the paper (primarily cellulose) reacts with oxygen in the air. This results in the formation of new substances like carbon dioxide, water, and ash. The paper loses electrons in this process, making it an oxidation reaction.
In summary: Burning is a classic example of oxidation because it involves a chemical reaction where a substance combines with oxygen, leading to the loss of electrons.
