How many atoms are represented in the formula CaCO3

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

Answer:100

Explanation:

CaCO3=40+12+3*16

=100