How does Avogadro's number relate to the concept of a mole?

Which of the following best describes an ion?

How many molecules are in 2 moles of water (H₂O)?

How many moles of oxygen atoms are in 88 grams of carbon dioxide (CO₂)? (Molar mass of CO₂ = 44.01 g/mol)

Calculate the molar mass of glucose (C₆H₁₂O₆).