Write the reaction in which "Philosopher's wool" is formed ?

Explanation

To write the reaction in which "Philosopher's wool" is formed, we need to identify the chemical process involved in its formation. Philosopher's wool is the common name for zinc oxide (ZnO).

### Step-by-Step Solution:

1. **Identify the Reactants**: The primary reactants involved in the formation of zinc oxide are zinc (Zn) and oxygen (O2).

2. **Write the Reaction**: When zinc is heated in the presence of oxygen, it reacts to form zinc oxide. The balanced chemical equation for this reaction is:
\[ 2 \text{Zn} + \text{O}_2 \rightarrow 2 \text{ZnO} \]

3. **Understanding the Formation of Philosopher's Wool**: The term "Philosopher's wool" refers to the white, fluffy product that is zinc oxide. This product can be collected as a residue after the reaction.

4. **Final Reaction**: The complete reaction can also be represented with water vapor (H2O) as follows, indicating that zinc oxide is formed along with hydrogen gas:
\[ 2 \text{Zn} + \text{O}_2 + \text{H}_2O \rightarrow 2 \text{ZnO} + \text{H}_2 \]

### Summary of the Reaction:
The reaction that forms Philosopher's wool (zinc oxide) is:
\[ 2 \text{Zn} + \text{O}_2 \rightarrow 2 \text{ZnO} \]