Which of the following is/are correct for group 14 elements?

Options

A. The stability of dihalids are in the order `CX_(2)+SiX_(2) lt GeX_(2) lt SnX_(2) lt PbX_(2)`
B. The ability of formm `p pi-p pi` multiple bonds among themselves increases down the group
C. The tendency for catenation decreases down the group
D. they all form oxides with the formula `MO_(2)`

Explanation

To determine which statements are correct for group 14 elements, we will analyze each of the provided statements step by step.

### Step 1: Identify the Group 14 Elements
Group 14 elements include Carbon (C), Silicon (Si), Germanium (Ge), Tin (Sn), and Lead (Pb).

### Step 2: Analyze the Stability of Dihalides
- **Statement 1**: The stability of dihalides increases down the group.
- **Explanation**: The dihalides of group 14 elements have the general formula MX2, where M is the group 14 element and X is a halogen. The stability of these dihalides increases from carbon to lead. The order of stability is:
- PbX2 > SnX2 > GeX2 > SiX2 > CCl2 (or CF2 for fluorides).
- **Conclusion**: This statement is **correct**.

### Step 3: Analyze the Ability to Form p-pi-pi Multiple Bonds
- **Statement 2**: The ability to form p-pi-pi multiple bonds among themselves increases down the group.
- **Explanation**: Carbon can form strong p-pi-pi multiple bonds due to its small size and effective orbital overlap. However, as we move down the group, the size of the atoms increases, leading to less effective overlap and a decrease in the ability to form such bonds. Heavier elements like tin and lead do not form p-pi-pi bonds.
- **Conclusion**: This statement is **incorrect**.

### Step 4: Analyze the Tendency for Catenation
- **Statement 3**: The tendency for catenation decreases down the group.
- **Explanation**: Catenation refers to the ability of an element to form chains or rings by bonding with itself. Carbon has a high tendency for catenation due to strong C-C bonds. As we move down the group, the bond strength decreases and the atomic size increases, leading to a decrease in catenation. Thus, the order of catenation is:
- C > Si > Ge > Sn > Pb (where Pb shows negligible catenation).
- **Conclusion**: This statement is **correct**.

### Step 5: Analyze the Formation of Oxides
- **Statement 4**: They all form oxides with the formula MO2.
- **Explanation**: Group 14 elements do form oxides when heated in oxygen, and they can form both mono oxides (MO) and dioxides (MO2). However, while all elements can form oxides, silicon dioxide (SiO2) is stable only at high temperatures, and lead can form PbO and PbO2. Thus, while they form oxides, the statement is slightly misleading.
- **Conclusion**: This statement is generally considered **correct** in the context of common oxides formed.

### Final Conclusion
The correct statements for group 14 elements are:
1. The stability of dihalides increases down the group (Correct).
2. The ability to form p-pi-pi multiple bonds decreases down the group (Incorrect).
3. The tendency for catenation decreases down the group (Correct).
4. They all form oxides with the formula MO2 (Correct).

Thus, statements 1, 3, and 4 are correct.