`p pi - p pi` multiple bond is seen in

Options

A. Mostly carbon
B. All carbon family member
C. Sn but not in carbon
D. Boron family and not in carbon family

Answer

To determine where the pπ - pπ multiple bond is seen, we need to analyze the options provided in the question.

### Step-by-Step Solution:

1. **Understanding pπ - pπ Bonds**:
- pπ - pπ bonds occur when there is a sideways overlap of p orbitals from two atoms. This type of bond is typically found in elements that can form double or triple bonds.

2. **Analyzing the Options**:
- **Option 1: Mostly Carbon**:
- Carbon (C) has the electronic configuration of 1s² 2s² 2p². It can form double bonds (C=C) through pπ - pπ overlap. Therefore, this option is correct.

- **Option 2: All Carbon Family Members**:
- The carbon family (Group 14) includes carbon (C), silicon (Si), germanium (Ge), tin (Sn), and lead (Pb).
- While carbon can form pπ - pπ bonds, silicon can also form pπ - dπ bonds due to the presence of vacant d orbitals. However, as we move down the group, the ability to form pπ - pπ bonds decreases due to increasing atomic size and decreasing effective overlap. Thus, this option is partially correct but not entirely true for all members.

- **Option 3: Sn but not in Carbon**:
- Tin (Sn) does not exhibit pπ - pπ bonding like carbon does. This option is incorrect because carbon does form pπ - pπ bonds.

- **Option 4: Boron Family and not in Carbon Family**:
- The boron family (Group 13) includes boron (B), aluminum (Al), gallium (Ga), indium (In), and thallium (Tl). Boron can form pπ - pπ bonds, but it does not have vacant d orbitals. Therefore, this option is also incorrect because boron can indeed form pπ - pπ bonds.

3. **Conclusion**:
- The correct answer is **Option 1: Mostly Carbon**, as carbon is the primary element where pπ - pπ multiple bonds are prominently observed.