Dipole-dipole forces act between the molecules possessing permanent dipole. Ends of dipoles possess 'partial charges'. The partial charge is

Options

A. more than unit electronic charge
B. equal to unit electronic charge
C. less than unit electronic charge
D. double the unit electronic charge

Explanation

**Step-by-Step Solution:**

1. **Understanding Dipole-Dipole Forces:**
- Dipole-dipole forces occur between molecules that have permanent dipoles. A permanent dipole arises when there is a significant difference in electronegativity between the atoms in a molecule, leading to an uneven distribution of electron density.

2. **Identifying Partial Charges:**
- In a molecule like water (H₂O), the oxygen atom is more electronegative than the hydrogen atoms. This results in the oxygen atom acquiring a partial negative charge (δ-) and the hydrogen atoms acquiring partial positive charges (δ+).

3. **Defining Partial Charges:**
- Partial charges (δ+ and δ-) are not full charges like the charge of an electron (approximately -1.6 x 10⁻¹⁹ coulombs). Instead, they represent a fraction of the full charge due to the unequal sharing of electrons.

4. **Comparing Partial Charges to Electronic Charge:**
- Since partial charges arise from the difference in electronegativity and the sharing of electrons, they are typically much smaller than the charge of a single electron. Therefore, we conclude that the magnitude of partial charges is less than the unit electronic charge.

5. **Final Conclusion:**
- Based on the above reasoning, the answer to the question is that the partial charge is less than the unit electronic charge.

**Answer: The partial charge is less than the unit electronic charge.**

---