Why `NiO` and `FeO` are nonstroichiometric with the formula `Ni_(0.98)O` and `Fe_(0.95)O`?

Explanation

To understand why \( \text{NiO} \) and \( \text{FeO} \) are non-stoichiometric compounds represented as \( \text{Ni}_{0.98}\text{O} \) and \( \text{Fe}_{0.95}\text{O} \), we need to explore the concepts of oxidation states and electrical neutrality in these compounds.

### Step-by-Step Solution:

1. **Definition of Non-Stoichiometric Compounds**:
Non-stoichiometric compounds do not have a fixed ratio of elements as described by a simple formula. Instead, they exhibit variations in composition due to the presence of vacancies or defects in their crystal lattice.

2. **Oxidation States of Nickel in \( \text{NiO} \)**:
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