Calcium carbonate (CaCO3): is a chemical compound that is found in nature as minerals such as calcite and aragonite. It is a common substance found in rocks such as limestone, marble, and chalk. It is also found in the shells of marine organisms and in pearls. Calcium carbonate has many uses, including as a filler in paint, as a component of cement, and as an antacid.
Sodium carbonate decahydrate (Na2CO3·10H2O): is a white, crystalline powder that is made by dissolving sodium carbonate (Na2CO3) in water. The "10H2O" in the chemical formula indicates that each molecule of sodium carbonate is hydrated with 10 water molecules. Sodium carbonate decahydrate is also known as washing soda or soda ash, and it is used in many industrial applications, such as in the production of glass, soap, and paper.
Sodium bicarbonate (NaHCO3): is a white, crystalline powder that is commonly known as baking soda. It is a mild alkali and is used as a leavening agent in baking, as a cleaner, and as an antacid. It is also used in the treatment of metabolic acidosis and in extinguishing fires.
These are three different compounds which are all made of carbon and oxygen, but they have different properties and uses.