Which element is used in the making of infrared `(IR)` windows, prism and lenses ?

Explanation

To solve the question of which element is used in the making of infrared (IR) windows, prism, and lenses, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Requirement**: The question asks for an element used specifically for making infrared windows, prisms, and lenses. This indicates that the element must have properties suitable for optical applications.

2. **Consider the Properties**: The ideal element for these applications should be transparent to infrared radiation. This means it must allow IR rays to pass through without significant absorption.

3. **Recall Relevant Elements**: We should think about elements known for their optical properties. One such group of elements is the carbon family (Group 14 of the periodic table).

4. **Identify the Element**: Within the carbon family, we look for an element with an atomic number of 32. This leads us to germanium (Ge), which is indeed a member of the carbon family.

5. **Confirm the Usage**: Germanium is known for its transparency to infrared light, making it suitable for the production of infrared windows, prisms, and lenses.

6. **Final Answer**: Therefore, the element used in making infrared windows, prisms, and lenses is **germanium**.