Chalk powder is a soft, white, fine-grained material primarily composed of calcium carbonate. It is derived from natural chalk, a type of limestone, which consists of the skeletal remains of marine organisms such as foraminifera and coccolithophores.

Chemical Formula: (CaCO₃)

Uses:

1. Education: Widely used in classrooms for writing on blackboards.
2. Industrial: It serves as a filler in rubber, paints, and plastics, and as a mild abrasive in household cleaning products.
3. Sports: Applied by athletes (e.g., gymnasts, weightlifters) to reduce hand moisture and improve grip.
4. Agriculture: It helps neutralize acidic soils by acting as a liming agent.

Chalk is non-toxic and generally safe for most applications.