The tibia and fibula are the two bones found in the human leg. The tibia, also known as the shinbone, is the larger and stronger of the two bones and is located on the inner side of the leg. The fibula is the smaller bone and runs parallel to the tibia on the outer side of the leg.

Chalk powder, which primarily consists of calcium carbonate, is relatively insoluble in water. While it can react very slowly with water over time to form soluble calcium bicarbonate, the solubility of chalk powder in water is extremely low, making it effectively insoluble for most practical purposes.