Which mineral is the major component of drywall? A. Talc C. muscovite mica B. Calcite D. selenite gypsum
The Correct Answer and Explanation is :
The correct answer is D. Selenite gypsum.
Explanation:
Drywall, also known as plasterboard or gypsum board, is primarily made from a mineral called gypsum (calcium sulfate dihydrate, CaSO₄·2H₂O). Gypsum is naturally occurring and can be found in various forms, including selenite, which is the crystalline variety of gypsum. The mineral gypsum has been used for centuries for construction purposes, and in drywall, it provides a smooth surface that can easily be covered with paint or wallpaper.
Gypsum is chosen for drywall because it is relatively lightweight, fire-resistant, and has a smooth texture that makes it easy to finish and paint. Drywall is created by placing a layer of gypsum between two sheets of thick paper. The gypsum in drywall is mostly in the form of a finely powdered or slurry mixture that is then dried and pressed between the paper layers.
The composition of gypsum allows it to act as a passive fire retardant because it contains water in its crystalline structure. When exposed to high temperatures, gypsum releases water vapor, helping to cool the material and slow the spread of fire. This property is one reason why gypsum is favored in the construction of fire-resistant walls.
To break down the other options:
- A. Talc is used in a variety of products like baby powder and some paints but is not a component of drywall.
- B. Calcite is a common mineral, mainly found in limestone and marble, but is not used in drywall.
- C. Muscovite mica is a mineral used in various applications like electronics and cosmetics but is not a major component of drywall.
Overall, the use of selenite gypsum in drywall contributes significantly to the performance and functionality of the material.
I’ll generate an image of drywall and gypsum.
Here is the illustration showing drywall with a close-up view of gypsum crystals. It depicts the crystalline structure of gypsum (selenite) inside the drywall. Let me know if you need more details or further clarification!
