What do you understand by (i) electron-deficient, (ii) electron-precise and (iii) electron-rich compounds of hydrogen? Provide justification with suitable examples.

Explanation

To understand the concepts of electron-deficient, electron-precise, and electron-rich compounds of hydrogen, we can break down the definitions and provide examples for each category.

### Step-by-Step Solution:

1. **Electron-Deficient Compounds**:
- **Definition**: Electron-deficient compounds are those that do not have enough electrons to form normal covalent bonds. This means they lack the necessary electron pairs to achieve a stable electronic configuration.
- **Examples**: The hydrides of Group 13 elements (the boron family) are classic examples of electron-deficient hydrides.
- **Boron Hydride (BH3)**: This compound has only six electrons around the boron atom, which is insufficient for forming three normal covalent bonds.
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