Why `BF_(3)` forms as an adduct with ammonia ?

Explanation

To understand why BF3 forms an adduct with ammonia (NH3), we can break down the explanation into several steps:

### Step 1: Identify BF3 as a Lewis Acid
- BF3 (Boron Trifluoride) is classified as a Lewis acid. This is because it has an incomplete octet; boron has only six electrons in its valence shell after forming bonds with three fluorine atoms.

### Step 2: Understand Electron Deficiency
- Due to its electron deficiency (having only six valence electrons), BF3 has a strong tendency to accept electrons to achieve a stable octet configuration. This characteristic makes it a good candidate for forming adducts with electron-rich species.

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