Which is the following properties describes the diagonal relationship boron and silicon?

Options

A. `BC l_(3)` is not hydrolysed while `SiCl_(4)` can be hydrolysed
B. Both form oxides `B_(2)O_(3)` is amphoteric and `SiO_(2)` is acidic
C. Both metals dissolve in cold and dilute nitric acid
D. Silicide and boride salts are hydrolysed by water

Answer

To determine which property describes the diagonal relationship between boron and silicon, we need to analyze the given options based on their chemical behavior and properties. Here’s a step-by-step solution:

### Step 1: Understand Diagonal Relationship
The diagonal relationship refers to the similarity in properties between elements that are positioned diagonally in the periodic table. In this case, boron (B) from group 13 and silicon (Si) from group 14 exhibit similar properties due to their positions.

**Hint:** Look for similarities in chemical behavior and properties between boron and silicon.

### Step 2: Analyze the Options
We have four options to consider. Let's evaluate each one:

1. **BCl3 is not hydrolyzed while SiCl4 can be hydrolyzed.**
- This statement is incorrect. BCl3 can hydrolyze to form BOH3 (boric acid) when treated with water, while SiCl4 can also hydrolyze to form Si(OH)4. Therefore, this option does not describe the diagonal relationship.

**Hint:** Check if both compounds can undergo hydrolysis.

2. **B2O3 is amphoteric and SiO2 is acidic.**
- This statement is true; however, it does not reflect a similarity in properties. The amphoteric nature of B2O3 and the acidic nature of SiO2 indicate different types of behavior. Thus, this option is not correct.

**Hint:** Compare the nature of oxides formed by both elements.

3. **Both metals dissolve in cold and dilute nitric acid.**
- This statement is partially true. Boron dissolves very little in cold nitric acid, while silicon forms oxides and does not dissolve significantly. This indicates a difference in behavior, so this option does not describe the diagonal relationship.

**Hint:** Consider the solubility of both elements in acids.

4. **Borides and silicides can be hydrolyzed by water.**
- This statement is correct. Both borides and silicides can react with water to form their respective hydroxides, indicating a similarity in their chemical behavior. This property reflects the diagonal relationship between boron and silicon.

**Hint:** Look for common reactions involving boron and silicon compounds.

### Conclusion
The property that describes the diagonal relationship between boron and silicon is that **borides and silicides can be hydrolyzed by water**. This reflects a similarity in their chemical behavior.

**Final Answer:** The correct option is that borides and silicides can be hydrolyzed by water.