Mass of each atom of carbon = 12
No of carbon atom = 6
Total mass of carbon atom = 12 X 6 = 72
Mass of each atom of hydrogen = 1
No of hydrogen atom = 12
Total mass of hydrogen atom = 1 X 12 = 12
Mass of each atom of oxygen = 16
No of oxygen atom = 6
Total mass of oxygen atom = 16 X 6 = 180
Total: 180 g / mole glucose
No of atoms = 200 g glucose / 180 g/mole glucose * 6.022 X 10^23 molecules glucose/mole glucose * 24 atoms/molecule glucose
= 16.044 X 10^24 atoms are present in 200 grams of glucose
Hope it helps!!!