Nucleophiles are __________ while electrophiles are __________ .

Options

A. Lewis bases, Lewis acids
B. Lewis acids, Lewis bases
C. Bronsted acids, Bronsted bases
D. Lewis acids Bronsted bases

Explanation

To solve the question "Nucleophiles are __________ while electrophiles are __________," we need to understand the definitions and characteristics of nucleophiles and electrophiles.

### Step-by-Step Solution:

1. **Define Nucleophiles**:
- Nucleophiles are species that have a tendency to donate an electron pair. They are often characterized by having a lone pair of electrons or a negative charge.
- This electron-rich nature allows nucleophiles to attack electron-deficient species (electrophiles).

2. **Identify the Role of Nucleophiles**:
- Nucleophiles act as Lewis bases. A Lewis base is defined as a substance that can donate a pair of electrons to form a covalent bond.

3. **Define Electrophiles**:
- Electrophiles are species that are electron-deficient and have a tendency to accept an electron pair. They are often positively charged or neutral molecules with an incomplete octet.
- Electrophiles seek electrons to complete their valence shell.

4. **Identify the Role of Electrophiles**:
- Electrophiles act as Lewis acids. A Lewis acid is defined as a substance that can accept a pair of electrons to form a covalent bond.

5. **Fill in the Blanks**:
- Based on the definitions and roles identified, we can fill in the blanks:
- Nucleophiles are **Lewis bases** while electrophiles are **Lewis acids**.

### Final Answer:
Nucleophiles are **Lewis bases** while electrophiles are **Lewis acids**.

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