Here's how to determine the number of atoms in the molecule C₂H₅NO₂:

* Count the subscripts:

* Carbon (C): 2 atoms

* Hydrogen (H): 5 atoms

* Nitrogen (N): 1 atom

* Oxygen (O): 2 atoms

* Total atoms: 2 + 5 + 1 + 2 = 10 atoms

Therefore, there are 10 atoms in the molecule C₂H₅NO₂.