Select correct statement(s) regarding `sigma and pi` bonds :

Options

A. `sigma`-bond lies on the line joining the nuclei of bonded atoms
B. `pi-` electron cloud lies on either side to the line joining the nuclei of bonded atoms
C. `(2ppi-3dpi)pi`-bond is stronger than `(2ppi-2pi)pi`-bond
D. `sigma`-bond has primary effect to decide direction of covalent bond, which `pi-` bond has no primery effect in direction of bond.

Answer

To solve the question regarding the correct statements about sigma and pi bonds, we will analyze each option based on the properties of these types of bonds.

### Step-by-Step Solution:

1. **Understanding Sigma Bonds**:
- Sigma bonds are formed by the head-on overlapping of atomic orbitals. This overlap occurs along the line connecting the nuclei of the two atoms involved in the bond.
- Sigma bonds are characterized by their cylindrical symmetry around the bond axis.

2. **Understanding Pi Bonds**:
- Pi bonds are formed by the side-to-side overlapping of p orbitals. This overlap occurs above and below the line connecting the nuclei of the bonded atoms.
- Pi bonds do not have a cylindrical symmetry like sigma bonds and are generally weaker than sigma bonds.

3. **Analyzing the Options**:
- **Option A**: "Sigma bond lies on the line joining the nuclei of bonded atoms."
- This statement is **correct** because sigma bonds are indeed formed along the line connecting the nuclei.

- **Option B**: "Pi electron cloud lies on either side of the line joining the nuclei of bonded atoms."
- This statement is **correct** as pi bonds have their electron density located above and below the line joining the nuclei.

- **Option C**: "2P pi and 3D pi that is pi bond is stronger than 2P pi 2 pi Pi-Pi bond."
- This statement is **incorrect**. Generally, 2p-2p pi bonds are stronger than 2p-3d pi bonds due to better overlap in similar types of orbitals.

- **Option D**: "Sigma bond has primary effect to decide direction of covalent bond which Pi bond has no primary effect in direction of bond."
- This statement is **correct** because sigma bonds determine the orientation of the molecule, while pi bonds do not influence the direction of the bond.

4. **Conclusion**:
- The correct statements regarding sigma and pi bonds are **Option A**, **Option B**, and **Option D**.

### Final Answer:
The correct statements regarding sigma and pi bonds are:
- Option A
- Option B
- Option D