Calcium carbonate has many different foods and medicines made from it such as toothpaste, lipstick, hair cream, limestone Countertops , paint, spackling Ink, and microwavable containers too. Also, calcium carbonate is used as a medicine to soothe heartburn, acid indigestion, and an upset stomach. Calcium is found in processed meat and fish products, dried fruits, canned sardines and in frozen foods. The molecular composition of calcium carbonate is CaCO3 which in this compound there is carbon, calcium, and three oxygen atoms. Calcium carbonate is an odorless, fine white powder. It has a density of 2.71 g/mL ,and a melting point of 1,339°C in its calcite form. Calcium carbonate is insoluble in water and stable at normal temperatures. When heated to high temperatures, it decomposes to form calcium oxide with the release of carbon dioxide. CaCO3 → calcium oxide calcium oxide is its molecular compound equation at high temperatures. CaCO3 also releases carbon dioxide when it is reacted with acids. Calcium carbonate reacts with water containing carbon dioxide to form the water soluble calcium bicarbonate salt (Ca(HCO3)2) which explains the chemical and physical properties of calcium carbonate. Calcium carbonate is not only in the medical field, but in engineering ,and architecture as well. It is often added as the ingredient in cement and for limestone to create roads.People who have swimming pools use calcium carbonate to maintain the alkalinity of the water.