The number of oxygen atoms = 3
Mass = 24 g
Further explanation
The formula of a compound shows the composition of the constituent elements
CaCO₃ is composed of 3 types of elements, namely Ca, C and O
The amounts of each of these elements in the compound CaCO₃:
So the number of oxygen atoms = 3
mass of Oxygen :
![\tt mass~O=(3* Ar~O)/(MW~CaCO_3)* mass~CaCO_3\\\\mass~O=(3* 16)/(100)* 50=24~g](https://img.qammunity.org/2021/formulas/chemistry/college/gaagvg8bwcpnmrz7kb6e4dmniflausxvb7.png)