1.5 mol of the complex substance carbon dioxide (CO2) is just a few oxygen atoms:

9.03 x 10²³atoms

Explanation:

Given parameters:

Number of moles of CO₂  = 1.5mol

Unknown:

Number of atoms  = ?

Solution:

In a mole of a substance, we have the Avogadro's number of particles which is 6.02 x 10²³atoms.

  Using this number, we can determine the amount of atoms in any substance.

If;

       1 mole of CO₂ contains 6.02 x 10²³ atoms;

     1.5mole of CO₂ will contain 1.5 x 6.02 x 10²³ atoms

                                                = 9.03 x 10²³atoms