Answer: Carbonic acid.
Explanation:
What is carbonic acid? Carbonic acid is a weak acid that forms when carbon dioxide gas and water chemically combine. Because carbon dioxide, CO2 must dissolve in water HO2 for carbonic acid to be present, one molecule of carbonic acid contains the same types of elements in the same proportions as carbon dioxide and water. Water contains two hydrogen atoms, and carbon dioxide has no hydrogen, so the resulting carbonic acid contains two hydrogen atoms. Water contains one oxygen atom and carbon dioxide contains two oxygen atoms, and this is why carbonic acid contains three oxygen atoms. Water has no carbon atoms, and carbon dioxide has one carbon atom, which explains why carbonic acid has just one carbon atom. The number of hydrogen, oxygen, and carbon atoms as separate carbon dioxide and water molecules or joined together as a carbonic acid molecule stays the same. Other names for carbonic acid are dihydrogen carbonate, and it is also known by its chemical formula H2CO3.
