`BF_(3)` is an acid , according to

Options

A. Lewis
B. Arrhenius
C. Bronsted and Lowery
D. All of the above

Explanation

To determine whether BF₃ is an acid, we can analyze it according to three different acid-base theories: Lewis, Arrhenius, and Bronsted-Lowry.

### Step-by-Step Solution:

1. **Understand the Definitions of Acids:**
- **Arrhenius Acid:** A substance that increases the concentration of H⁺ ions in aqueous solution.
- **Bronsted-Lowry Acid:** A substance that donates protons (H⁺ ions).
- **Lewis Acid:** A substance that accepts electron pairs.

2. **Analyze BF₃:**
- BF₃ (Boron Trifluoride) is a compound where boron has an incomplete octet, meaning it can accept electrons.
- It does not donate protons (H⁺ ions) nor does it increase the concentration of H⁺ in solution.

3. **Determine the Type of Acid:**
- Since BF₃ can accept electron pairs, it fits the definition of a Lewis acid.
- It does not fit the definitions of Arrhenius or Bronsted-Lowry acids because it does not release H⁺ ions or donate protons.

4. **Conclusion:**
- Therefore, BF₃ is classified as an acid according to the Lewis theory.

### Final Answer:
BF₃ is an acid according to the Lewis theory.