Question

what is the difference between no of gram atoms and no of atoms?​

Answer 1

Gram of atoms" is in the normal English sense. If you say 10 grams OF atoms, it can be 10 grams of any atoms. Could be 10 grams of Hydrogen atom or Oxygen atoms or Na atoms. And the number of atoms in each of this samples will be different

Answer 2

Good question

See if there is a specific compound for example O2 ( Oxygen) then it has a fixed no. of atoms in any mass either it may be in gram or in killogram or in milligram .

for example O2 has 2×8=16 atoms

These 16 atoms will be also there in 0.1 gram or 1000 kg or else.

Where as no. of gram gives us idea of amount of the commodity such as 28g or 293kg etc of a specific thing.

One more thing is that attomic no. is the sum of protons and neutrons in any specific atom .Where mass specifies the quantity.