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

To solve the question regarding the nature of partial charges in dipole-dipole interactions, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Concept of Dipole-Dipole Forces**:
- Dipole-dipole forces occur between molecules that have permanent dipoles. This means that these molecules have regions of partial positive and partial negative charges due to differences in electronegativity between bonded atoms.

2. **Define Partial Charges**:
- A partial charge (denoted as δ+ or δ-) arises when there is an unequal sharing of electrons between two atoms in a molecule. This results in one atom being slightly more positive (partial positive charge) and the other being slightly more negative (partial negative charge).

3. **Compare Partial Charges to Unit Electronic Charge**:
- The unit electronic charge (denoted as e) is the charge of a single electron, approximately equal to \(1.6 \times 10^{-19}\) coulombs.
- Partial charges are not full charges; they represent only a fraction of the electronic charge due to the unequal sharing of electrons.

4. **Conclusion about Partial Charges**:
- Since partial charges are derived from the distribution of electrons and are not full charges, they are always less than the unit electronic charge. This means that the magnitude of a partial charge is less than \(1.6 \times 10^{-19}\) coulombs.

5. **Select the Correct Answer**:
- Based on the understanding that partial charges are less than unit electronic charges, the correct answer to the question is: "less than unit electronic charge."

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