Which of the following statement is/are correct ?

Options

A. All `III` A group elemts froms trihalide
B. Only `Al` react dirrelly with `N_(2)` at high temperature and form `AIN`
C. Al Passivated by concentrated `HNO_(3)`
D. All `IV A (14^(th))` group elements forms trihalide.

Explanation

To determine which statements are correct regarding the p-block elements, specifically the boron and carbon families, let's analyze each statement step by step.

### Step 1: Analyze Statement A
**Statement A:** All group 13 elements form trihalides.

- The group 13 elements (also known as the boron family) include boron (B), aluminum (Al), gallium (Ga), indium (In), and thallium (Tl).
- These elements can indeed form trihalides (e.g., BCl3, AlCl3).
- Since they exhibit a +3 oxidation state, they can bond with three halogen atoms.

**Conclusion for Statement A:** This statement is **correct**.

### Step 2: Analyze Statement B
**Statement B:** Only aluminum reacts directly with nitrogen at high temperature to form aluminum nitride.

- Both boron and aluminum can react with nitrogen at high temperatures.
- Boron reacts with nitrogen to form boron nitride (BN), while aluminum reacts to form aluminum nitride (AlN).
- Therefore, the statement that only aluminum reacts is **incorrect**.

**Conclusion for Statement B:** This statement is **false**.

### Step 3: Analyze Statement C
**Statement C:** Aluminum is passivated by concentrated HNO3.

- When aluminum is treated with concentrated nitric acid (HNO3), it forms a protective layer of aluminum oxide (Al2O3).
- This oxide layer prevents further reaction of aluminum with nitric acid, effectively passivating the metal.

**Conclusion for Statement C:** This statement is **correct**.

### Step 4: Analyze Statement D
**Statement D:** All group 14 elements form trihalides.

- Group 14 elements (carbon family) include carbon (C), silicon (Si), germanium (Ge), tin (Sn), and lead (Pb).
- These elements typically form tetrahalides (e.g., CCl4, SiCl4) due to their +4 oxidation state.
- Therefore, the statement that they form trihalides is **incorrect**.

**Conclusion for Statement D:** This statement is **false**.

### Final Conclusion
The correct statements are **A and C**.