Answer:
5 Atoms
Explanation:
Ca: calcium, has no numbers after is, which means its the only on of its kind in this chemical equation
C: carbon, also has no following numbers meaning its the only one.
O3: oxygen has a number 3 behind it so that tells you how many of the oxygen atoms there are.
Adding them up you have five total; 1Calcium+1Carbon+3Oxygen=5 Atoms
