CO2 (carbon dioxide) is a gas which is present in our atmosphere and is released during the combustion of fossil fuels.

K2CO3 (potassium carbonate) is a white salt that is commonly used in the production of glass and soap.

CaCO3 (calcium carbonate) is a white mineral that is found in rocks. It is used in a wide variety of applications, including in the production of cement, paper, and plastics.

Co (cobalt) is a transition metal that is commonly used in the production of magnets, batteries, and paint.