Drywall, also known as gypsum board, is primarily composed of gypsum, a naturally occurring mineral. Here's a breakdown of its chemical makeup:

* Gypsum (CaSO₄·2H₂O): This is the main component, providing the board's structure and fire resistance.

* Paper: Two layers of paper, one on each side of the gypsum core, provide strength and allow for easy installation.

* Additives: Small amounts of other ingredients are added to the gypsum to enhance its properties. These can include:

* Fiber: Adds strength and prevents cracking.

* Retardant: Improves fire resistance.

* Binder: Holds the ingredients together.

* Coloring agents: Provide a uniform color to the board.

So, while gypsum is the primary ingredient, it's the combination of all these elements that gives drywall its unique properties and makes it such a popular building material.