One element which is used in flash light in photography, when heated with alkyl halide, gives an organometallic compound. The element is:-

Options

A. Calcium
B. Tungston
C. Mangenese
D. Magnesium

Answer

To solve the question, we need to identify the element used in flash photography that, when heated with alkyl halides, produces an organometallic compound. Let's break down the solution step by step:

### Step-by-Step Solution:

1. **Understanding the Context**: The question mentions an element used in flash photography. Flash photography requires a bright, short burst of light to illuminate a scene.

**Hint**: Think about the materials historically used in flash photography.

2. **Identifying the Element**: In the early days of photography, magnesium was commonly used in flash powder. Magnesium burns brightly and produces a significant amount of light, making it suitable for photography.

**Hint**: Recall the properties of magnesium and its historical use in photography.

3. **Reactions with Alkyl Halides**: The question specifies that this element, when heated with alkyl halides, forms an organometallic compound. Magnesium can react with alkyl halides to form Grignard reagents, which are important organometallic compounds.

**Hint**: Consider the types of reactions that metals can undergo with alkyl halides.

4. **Conclusion**: Based on the above points, the element used in flash photography that gives an organometallic compound when heated with alkyl halides is magnesium.

**Final Answer**: The element is **magnesium**.