Sodium metasilicate and silica gel are both compounds derived from silica, but they have different chemical properties and uses.

1. Sodium Metasilicate:
Sodium metasilicate is an inorganic compound with the chemical formula Na2SiO3. It is formed by combining silica (SiO2) with sodium carbonate (Na2CO3) through a high-temperature fusion process. It exists as a white or colorless crystalline solid or as a white powder. Sodium metasilicate is highly alkaline and is commonly used in various industrial applications, such as detergents, cleaning agents, metal cleaning, water treatment, and as a cement binder.

2. Silica Gel:
Silica gel is also an inorganic compound made from silica (SiO2). However, unlike sodium metasilicate, silica gel is amorphous and comes in the form of small, porous, and irregularly shaped beads or granules. These porous particles have a high surface area, which allows them to adsorb and hold moisture. Silica gel is often used as a desiccant (a substance that absorbs moisture) to protect goods and products from humidity during transportation and storage. It is commonly found in packages with products like electronics, leather goods, and pharmaceuticals.

In summary, both sodium metasilicate and silica gel are derived from silica, but sodium metasilicate is an alkaline crystalline compound used in various industrial applications, while silica gel is an amorphous desiccant material utilized to control moisture in packaging and storage.