Dear Student,
Mass of 1 particle = 6.664 x 10-23 gm
1 Gram particle = mass of 1 mole iotas = 6.023x 1023 x mass of one molecule
=6.023x 1023 x6.664 x 10-23= 40.13 gm = 0.004 kg
Along these lines,
Number of gram particles in 40 kg = 1000.
Cheers!!
Regards,
Vikas (B. Tech. 4th year
Thapar University)