Which of the following can conduct electricity in?

Options

A. `MgBr_(2)`
B. `CaBr_(2)`
C. `BaBr_(2)`
D. `BeBr_(2)`

Explanation

To determine which of the following compounds can conduct electricity in the fused state, we can follow these steps:

### Step 1: Understand the Requirement for Conductivity
To conduct electricity, a substance must have charged particles that are free to move. In the case of ionic compounds, these charged particles are ions. In the solid state, ionic compounds do not conduct electricity because their ions are fixed in place within a crystal lattice. However, when they are melted (fused), the ions become free to move, allowing for the conduction of electricity.

**Hint:** Remember that only free-moving charged particles can conduct electricity.

### Step 2: Identify the Nature of the Compounds
We are given three ionic compounds: MgBr2, CaBr2, and BaBr2. All of these compounds are ionic in nature, which means they consist of positive and negative ions.

**Hint:** Check if the compounds are ionic; ionic compounds typically consist of metals and nonmetals.

### Step 3: Analyze the Fused State
In their molten (fused) state, ionic compounds dissociate into their respective ions. Therefore, MgBr2, CaBr2, and BaBr2 will all have free ions when melted, allowing them to conduct electricity.

**Hint:** Think about what happens to ionic compounds when they are heated to their melting points.

### Step 4: Consider the Fourth Option
The fourth option is BeBr2. This compound is not purely ionic; it exhibits covalent character and does not dissociate into free ions in the same way that the other three compounds do. Instead, BeBr2 exists in a polymeric structure and does not have free-moving ions in its solid or molten state.

**Hint:** Identify if the compound is covalent or has significant covalent character, as this affects its ability to conduct electricity.

### Step 5: Conclusion
Based on the analysis, the compounds that can conduct electricity in the fused state are MgBr2, CaBr2, and BaBr2. The compound BeBr2 cannot conduct electricity due to its covalent nature.

**Final Answer:** The correct options are MgBr2, CaBr2, and BaBr2. BeBr2 does not conduct electricity.