1. Find the molar mass of Cu(NO3)2

* Cu: 63.55 g/mol

* N: 14.01 g/mol (x2 because there are two nitrogen atoms)

* O: 16.00 g/mol (x6 because there are six oxygen atoms)

Molar mass of Cu(NO3)2 = 63.55 + (14.01 x 2) + (16.00 x 6) = 187.57 g/mol

2. Calculate the number of moles of Cu(NO3)2

* moles = mass / molar mass

* moles = 14.0 g / 187.57 g/mol = 0.0746 moles

3. Determine the number of moles of oxygen atoms

* There are 6 moles of oxygen atoms for every 1 mole of Cu(NO3)2.

* Moles of oxygen = 0.0746 moles Cu(NO3)2 * (6 moles O / 1 mole Cu(NO3)2) = 0.4476 moles O

4. Calculate the number of oxygen atoms

* Use Avogadro's number (6.022 x 10^23 atoms/mol) to convert moles of oxygen to atoms.

* Number of oxygen atoms = 0.4476 moles O * (6.022 x 10^23 atoms/mol) = 2.69 x 10^23 oxygen atoms

Therefore, there are approximately 2.69 x 10^23 oxygen atoms in a 14.0 g sample of Cu(NO3)2.