Respuesta :

Dejanras
Answer is: 60.
In one molecule of C₂₀H₄₂S₃O₂, there is 2 atoms of oxygen (subscript after oxygen indicates number of atoms of oxygen in chemical (molecular) formula).
So, in 30 molecules of C₂₀H₄₂S₃O₂, there is: 30·2 = 60 atoms of oxygen.