For the formation of covalent bond, the different in the value of electronegativities should be

Options

A. Equal to or less than 1.7
B. More than 1.7
C. Exactly equal to 1.7
D. Nothing can be said

Answer

To determine the difference in electronegativities required for the formation of a covalent bond, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Electronegativity**: Electronegativity is a measure of the tendency of an atom to attract a bonding pair of electrons. The difference in electronegativities between two atoms can help predict the type of bond that will form between them.

2. **Types of Bonds**: There are generally three types of bonds based on electronegativity differences:
- **Covalent Bonds**: Formed when the electronegativity difference is small.
- **Ionic Bonds**: Formed when the electronegativity difference is large.
- **Polar Covalent Bonds**: Intermediate between covalent and ionic bonds.

3. **Electronegativity Difference Values**:
- If the difference in electronegativities is **equal to or less than 1.7**, the bond is considered a **covalent bond**.
- If the difference is **greater than 1.7**, the bond is considered an **ionic bond**.

4. **Conclusion**: For the formation of a covalent bond, the difference in the value of electronegativities should be **equal to or less than 1.7**.

5. **Final Answer**: Therefore, the correct option is **A: equal to or less than 1.7**.