why does white Zn0(s) becomes yellow upon heating ?

Explanation

To understand why white ZnO (zinc oxide) becomes yellow upon heating, we can break down the explanation into a series of steps:

### Step 1: Understanding the Structure of ZnO
Zinc oxide (ZnO) is a crystalline solid that typically appears white in its pure form. In its structure, ZnO consists of zinc ions (Zn²⁺) and oxide ions (O²⁻) arranged in a specific lattice.

**Hint:** Recall that the color of a compound can be influenced by its crystal structure and the presence of defects or impurities.

### Step 2: Heating ZnO
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