Which of these is pyroelectric?

Options

A. NiO
B. `Co_(3)O_(4)`
C. `Cr_(2)O_(3)`
D. Lithium

Answer

To determine which material is pyroelectric, we need to understand the definition and characteristics of pyroelectric materials. Here’s a step-by-step solution:

### Step 1: Understand Pyroelectricity
Pyroelectric materials have the ability to generate a temporary voltage when they are subjected to a change in temperature. This means that when these materials are heated or cooled, they produce an electric charge.

**Hint:** Remember that pyroelectricity is related to temperature changes in materials.

### Step 2: Identify Common Pyroelectric Materials
Common pyroelectric materials include certain types of crystals and ceramics. Some well-known examples are:
- Lithium tantalate (LiTaO3)
- Triglycine sulfate (TGS)
- Barium titanate (BaTiO3)

**Hint:** Look for materials that are often used in sensors and devices that rely on temperature changes.

### Step 3: Analyze the Given Options
In the question, we are provided with several options, and we need to identify which one is pyroelectric. Based on the knowledge of pyroelectric materials, we can evaluate the options.

**Hint:** Compare the options against the list of known pyroelectric materials.

### Step 4: Determine the Correct Answer
From the analysis, we find that Lithium (specifically, Lithium tantalate) is a well-known pyroelectric material. Therefore, among the options provided, Lithium is the correct answer.

**Hint:** If you remember that Lithium is often associated with pyroelectric properties, it will help you identify the correct option.

### Conclusion
The correct answer to the question "Which of these is pyroelectric?" is **Option 4: Lithium**.

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