Final answer:
There are six oxygen atoms in each formula unit of calcium bicarbonate.
Step-by-step explanation:
The chemical formula for calcium bicarbonate is Ca(HCO3)2. To determine the number of oxygen atoms in each formula unit of calcium bicarbonate, we need to count the number of oxygen atoms in the carbonate ion (CO3)^2-. The carbonate ion consists of one carbon atom and three oxygen atoms. Since each formula unit of calcium bicarbonate contains two carbonate ions, there are a total of six oxygen atoms in each formula unit of calcium bicarbonate.