Number of particles of water = avogadro constant x amount in molTherefore6.02 x1023 x 0.75= 4.515 x1023There are 3 atoms in every molecule of water so we need to multiply the number of particles by 34.515 x1023 x 3 = 1.3545x1024Rounded to 2 decimal places the answer is 1.35x1024